I'm your worst nightmare. A parent-sponsored deb dropped in on the pretence of contacts and networks. My genetic investors were impressed that I'd managed to swap details with Todd, a screenwriter in his early fifties, after an event at the Santa Barbara Film Festival, maybe even a little taken aback. After a rocky mid-teens, this late-teens version of their offspring was getting a bit of confidence, in the area where it counted most if she was going to have the creative career she wanted. Todd spoke to my parents in turn, on landlines no less, assuring them of his credentials to chaperone me around Los Angeles for a couple of weeks. He was practically, though not legally, a stepfather to his ex-partner's daughter for over a decade. I'd had plenty of babysitters with less experience. Admittedly, they had all been young women that my mum had met in person before hiring. But, for all of Todd's enthusiasm and lofty art chat, he wasn't a sleaze. For gas money, he'd be my guardian and guide.

So I found myself in the Sportsman's Lodge, in a poolside room, after Todd deemed my humble Best Western unacceptable, gaining permission and cash from my parents once more. At the Sportsman's Lodge, swans strut about the grounds and every surface is covered in reassuringly dark wood. Its grand crescent entrance cameos in an episode of Arrested Development. I was more excited to ease my jet lag by crossing the road to the 24-hour Ralph's to raid the eerily lit salad bar. A supermarket chain elevated in my mind thanks to being featured for a handful of shots in The Big Lebowski. Even the normal stuff was fit to revere.

LA is peppered with celebrities but there wasn't the constant stream of stars I'd been led to expect. Turns out that LA is, first and foremost, a city. It takes a lot of ordinary people to keep a city a city. Celebrities aren't just like us but they can't escape the need for goods and services. When buying my brick of a US burner phone, Todd introduces me, in one full sweep of seizing the moment, to Forest Whitaker. Todd did not personally know Forest Whitaker. We all shake hands. Forest's wife has the widest smile and brightest eyes. He seems as tired as I am but graciously listens to me, hallucinatory with fatigue. He and his wife buy the iPhone, one each. Thanks to Todd, I'd got my first impressive anecdote.

Todd was most definitely not a sleaze but his dress sense was sleaze adjacent. Hawaiian shirts in muted tones, Levi's, cowboy boots, huge square-framed glasses. He drove a compact, bright red convertible, with an ever-ready supply of individually wrapped mints in the little compartment by the gear stick. No one walks anywhere. Todd would drive me around, enthusiastic and encouraging of my wide-eyed regard for this place I was scoping for my future flourishing. He regaled me with his tales of projects gone awry, his stint in the editing team of the Playboy Book Club, the doctoring he did for a young adult sci-fi franchise, all mixed in with his staunch study of Eastern philosophy and esoteric spirituality.

"My stepdaughter went here," he said, as we crawled past a building that looked like a school. "I picked her up once," he continued, battling against the volume of the air streaming over us, "and she'd been talking to her friend whose parents were getting divorced. That girl was Angie Voight, who grew up to be..."

"Angelina Jolie!" I said, out of sheer amazement.

"Yeah, her," he said, a little perturbed I'd taken his reveal.

What must have people thought when they saw us, this mismatched duo? The security guard in Chanel on Rodeo Drive couldn't help but change his posture when we walked in. I hovered over the beautiful things, taking them in like any artefact in a museum, while Todd stood a few metres behind, hands firmly in his pockets.

I had hoped that actually being in LA would make me feel part of it all. Now I was here, I was close but I couldn't shake the distance. I'd managed to lose a pair of Vivienne Westwood sunglasses that my friend had gifted me.

"Jesus, Lolly," I gasped, "Are you sure?"

"Remember, my dad's an optician, they cost, like, nothing to him," she grinned. I breathed a low, long sigh of relief and wore them incessantly.

Until I left them in an Urban Outfitter's changing room. Running back into the store five minutes later, they were gone. Of course they were. Squinting against the sunlight, I made the tiny walk back to the Sportsman's, a journey that the receptionist almost insisted I take a cab for, and flopped face forward onto the bed. The splashing of the younger guests a few feet away sounded like a blazing row. I'd chosen this trip of all trips to read The Bell Jar. "Huh, shit," I thought, as Esther detachedly recounted her big break with Ladies' Day in the other city. Not just me. Not just now. Not just here. I closed the room curtains to watch I Love Lucy reruns without the glare, turned up the AC and buried myself under the covers.

I did do some work. Well, work experience, which often translated into being present while work occurred. I had two days with the camera crane rental company, run by one of Todd's friends, Wayne. Wayne was a skyscraper, drove a Harley Davidson, and knew Dr Dre pretty well. Early to fatherhood, he had a young grandson he adored. Tough and soft, like anything wild. The first day of work experience was spent in the office. Me, Wayne, and Wayne's business partner. They had a stack of admin to get through and didn't know what to do with me, so they put There Will Be Blood On the tiny TV and DVD combi. The second day of work experience, they took me along to a gig, on location for Johnny Lee Miller vehicle Eli Stone, where none other than Katie Holmes had a guest spot. I heard the crew through the walkie talkies bleat at each other like sheep. I ate a hot, sloppy plate at craft services. I watched Katie Holmes's hairdresser comb her fringe between each and every take. I got hit on by a weird medic. I made eye contact with Johnny Lee Miller. I saw Tom Cruise from afar, bouncing Suri in his arms, as he purred, "She's great, she's great...", clearly not talking about his wife or his daughter. Rows and rows of Jamba Juice smoothies were laid out on collapsible tables. Production told us to help ourselves - a gift from Katie.

"Careful," said Wayne, "a Scientologist might appear and ask you if you're stressed."

Wayne clearly didn't suffer fools. He was one of those men made for myth. Todd referred to him almost exclusively by his full name, with the prefix, "the wondrous." Like a movie title.

Tina was Todd's real best friend. She was tiny, in every direction. A plastic Big Gulp was permanently glued to her hand, almost as if she wanted to provide a point of contrast to emphasise her petiteness. She wore flowing skirts and vest tops, her shiny hair hanging long down her back. Her voice was husky and she had a brilliant laugh. She had been an air hostess for private jets, once serving George Clooney. I imagined him making her laugh her laugh and it made me feel warm, brighter. We would hang out at Casa Vega, a legendary Mexican bar and restaurant. Todd had first met Tina here. And Wayne. I loved it. It was full of life, made in the old style and kept that way. It had its own pulse, the steady swoosh-swoosh of margaritas getting shaken.

"I saw Pink here once," said Todd.

"Oh, I love her!"

"Seemed like she was having a fight with her partner in the parking lot." I decided against taking a photo.

Todd and Tina would say hi to the staff and the other regulars. They'd each have two margaritas and strictly no more, while I snacked on a guacamole bowl. The bowl was edible, tortilla baked into a deep well shape. It was intended an appetizer to share but worked as a vegan entrée, too. Being a vegan back at home was frowned upon and poorly served. Here, I had one of the most basic diets around. I'd managed to stop rigidly calorie counting but I had to make concessions somewhere if I was going to be thin. Just the chef's salad - hold the eggs, cheese, and ham - and a grapefruit juice for me, thanks.

After a good couple of hours at Casa Vega, we headed back to Casa Tina's, a symphony in rich jewel-tones, mainly ruby. Billowing fabric was strung up from the ceilings, turning it into a luxury tent. It was an astonishing fire hazard and quite beautiful. Now on private property, we could share a bottle of red wine together. I could finally be an adult with my adult friends. Todd had gathered us here for a viewing of his favourite film, one he'd raved about from the moment we'd met.

It was called Petulia. Set in Swinging Sixties' San Francisco, directed by Richard Lester, and starring Julie Christie and George C. Scott. It's hard to summarise neatly, like all the best films. On the surface, it's this age-gap romance of two achingly sad people, but it's also this weirdly prescient, richly textured story of generational and cultural clashes. The interiority of the whole world comes through, discordant and confusing.

"You enjoy playing poverty, don't you?" an African-American cashier says to a white hippie stoner, in a shouting match about sardines.

"That's when 24/7 markets were just coming around," Todd noted for my benefit.

We watched Petulia fall apart in a proto-Manic Pixie Dream Girl fashion, emphasis on the fashion.

"All this I Love Lucy jazz, it's only cute for a while," barked George C. Scott.

My ears perked up. George C. Scott was right. I have to make the most of being here while I'm here, I resolved, before sleep took me. After this viewing, Todd took to calling me Emilia.

Tina accompanied us to one of the jewels in my trip, a screening at the Arclight to celebrate the DVD release of Spaced, followed by a Q&A with Edgar Wright, Jessica Stevenson, and Simon Pegg, hosted by Kevin Smith. My favourite people, all together in one place. I'll figure out how to meet them, find them back in England, get work as a runner on their next projects and then my life will really start. The event was first come, first served, and I woefully underestimated the pull of a cult British TV show on LA's more discerning crowd.

"What a line!" squawked Tina.

Dutifully taking our place, I stand so I can hop from foot to foot, nervous about getting inside, while Todd and Tina sat on the ground, chirping away.

"Hey, you two," I say, holding up my digital camera, gesturing them to get closer.

Tina and Todd lean in and pucker, as if to share the straw. Click. We make it inside. I bide my time until the Q&A, make a bit of a scene. Afterwards, through the combined English powers of a certain accent, self-deprecation, and manners, I get to have a chat with Simon Pegg. He gives me a proper hug before joining his wife to celebrate their anniversary. What a really nice and funny and successful person, I think. He deserves everything, maybe it's possible for me too, and I glow the entire drive to the Sportsman's. On the PC in the lobby, I check my email and MySpace messages. I feel better telling people about what I've been doing. Better, perhaps, than how I feel when I'm actually doing it. After some USB-cable wrangling, I manage to post the photo I took of Todd and Tina to Facebook. I caption it, "My LA parents." I refrain from making a joke about dysfunctional families.

Sure, there were some weird things about Todd. I couldn't shake the look of polite panic in the much younger eyes at the offices we visited. He wasn't cool, he was hip, and people received that awkwardly, if at all. He wasn't deceitful or harmful. His favourite film was based on a book that called its main character the arch kook. Tina was pretty weird too. Wayne went his own way. Just a nice collection of American eccentrics, enhancing my life with theirs, so different from mine. There was only one thing about Todd that truly unnerved me.

I noticed that it was customary for restaurants, from low to high on the invisible but tangible scale, to have a deep goblet of individually wrapped mints, about hip-height, by the entrance, near the reservations book. A little touch of hospitality for incoming or outgoing guests. We rarely ate out - I had a cash allowance and an eating disorder to manage - but we walked near plenty of restaurants. Without fail, Todd would divert his course, pause by the front door, plunge his open hand into the mints to wrist-level, then pull up a bulging fist. He'd shove them into his jean pockets and we'd crackle back to his car, where he'd replenish the supply of his stash. No one would stop him doing this, though I desperately wanted to.

"They're free," he said, "they want you take them." As if that made it all right.

Todd didn't talk much about where he came from, who he grew up with. There was barely any mention of his mother. Once, a swift arc of disdain for his brother. Nothing about his father. So when he said let's stop by his place before going on elsewhere, I wasn't scared, I was intrigued. Loud, present people have their own mystery. Todd's apartment was immaculate. Bright white, not a thing out of place. Not that there were many things at all, including signs of life. I couldn't believe that anyone was living there, let alone Todd. It felt like he was about to sell it to me. Maybe there wasn't much left over in the budget to decorate once he'd got the convertible. He boldly tapped one of the few hanging frames. I squinted and saw it wasn't a picture but text. The First Amendment.

"Without this, we're fucked."

He stood in awe of it, chest puffed up and out. I froze, which I hoped he took as reverence. He said he wanted to show me something else and rushed into one of the few doors. I wasn't afraid. I just couldn't move.

"Remember in American Beauty," he called out, "when Lester buys the Pontiac Firebird?"

"Uh-huh," I mumbled, having watched American Beauty almost every weekend since I recorded it from BBC2.

Todd emerged with a suede jacket in a deep tan shade, heavily fringed and swaggering from its hanger.

"This is my Pontiac Firebird." He grinned at me before punching the air. "I rule!"

So dreams can come true, of any size. I began to think about what my Pontiac Firebird was but a kick in my brain reminded me that I'd lost my Vivienne Westwood sunglasses. In such a stupid way, too. If you can't be clever, better not to have anything that valuable.

On my penultimate night, we drove high up with Tina to perch on the precipice, looking down into and across the valley. The fireworks for independence were bursting all over the city, like popcorn kernels over one big, black burner. The next day, Wayne invited me to a job on set for the latest Garry Marshall movie, which meant changing my flights. Maybe I'd even see Julia Roberts. I politely declined, despite Todd and Wayne's protests that this could be really good for my career. If it was anything like the day on Eli Stone, I'd field some creeps and watch from afar. I was ready - and eager - to go home. Besides, I'd be back.

None of this went on my CV. It lived in me, as any experience does, and that was the true credential. Todd and I kept up an email correspondence. I'd pour my heart out about where I was at, personally and career-wise. Though it was mainly the former, I referred to him as, "my sort of mentor". He'd reply in kind, "Hey, Emilia...!" These essays going back and forth across the pond. There wasn't much talk about the industry, a smattering of politics. He kept me up to date on the drifts in his friendship group, including a forensic recounting of his falling out with Tina over her forgetting to return his "pasta pot". He still championed my ideas, without reading much of what I'd written. I did read his scripts. They were perfectly paced, robustly structured, but somehow completely out of time. Todd wanted them to be made so much, not for his own ego, but for what he believed cinema could, and really should, be. And I wanted that too.

When landline plans allowed, we'd speak on the phone. One evening, a little flushed from red wine and the confidence of living alone in my own flat, I told him how much he meant to me, how much he'd done for me, and, for all these things, I loved him.

"You too," he cleared his throat.

So when, a few months later, Todd told me about his publisher reneging on a deal for a new book, leaving him in financial dire straits, I offered to lend him money. He wouldn't have to work so hard at the call centre, polling citizens for tidbits about their political leanings. A chance for me to help out my friend for a change! Through the magic of internet banking, about three hundred of my pounds would be winging their way to him, magically turning into dollars.

But Todd didn't have internet banking. Why hadn't I gone to my bank and sent a cheque? I apologised, stinging. Todd would call me from his bank, handing me over to the teller, to explain the status of the transfer. I told the teller what my bank told me, that international transfers could take up to a working week. The teller sounded exasperated. Todd sounded manic. I felt sick, not from shock, but from the sense that this had always been the case, and I was nothing more than a mark.

The calls became daily. I ignored them, following up instead with emails composed by my friends with the best boundaries. Todd switched his tone between passive aggression, if he didn't accept my explanation, the only one I had about how the modern world of banking worked, and placating if I called him out on how weird he'd become. It was the strangest week and a half of my life. When the money finally came back to me, six months later, it was via cheque. Once it cleared, I cut all contact with Todd. Not that he didn't try to get back in touch, the previews of his messages filled with the same breezy, "Hey, Emilia...!"

I haven't been back to LA. I haven't created the life I wanted when I had more life ahead of me. I have watched Petulia again recently. It's still vivid, irreverent, exquisite. I dare you to find another better opening fifteen minutes of anything. Anticipating their first tryst, Petulia and Archie walk a forbidden path for pedestrians, a steep ramp meant for cars, to their motel room. Archie mutters, "Charming," under his breath. Petulia, not missing a beat, keeps walking, and almost wails, "No, no, you don't understand, it shouldn't be charming. You're missing the whole point. It should be menacing, grey, terribly distraught!"

They don't become lovers, not that night. Petulia arrives at Archie's house the next morning brandishing a tuba, before fainting. Archie brings her round with smelling salts. She's convinced she's broken a rib. She looks up at him from under her artfully dishevelled fringe.

"Kooky though, isn't it?"