Wanted: an athletic, handsome man aged 19-23 and a street-smart and strong girl in her late teens. That was the casting call sent out by Disney as it appealed for unknown actors across Britain to audition for a part in the next instalment of Star Wars.

This seems like as a good opportunity for me to leave behind the bleak world of freelance journalism and head on the road to fame, so I head to the first audition in Bristol. As far as I can tell, there are only two things standing in my way.

First, I've never acted. I was once talked into auditioning for a Talk to Frank anti-cocaine advert, but on the day of the audition I had a terrible cold.

Second, and this is a bit of a bombshell, I've never seen Star Wars. I feel like I can remedy both of these on the train down. I text my actress friend Emer asking advice on auditions. She tells me: "Act natural. Remember to breathe. And failing that, drink a Diet Coke and a beer simultaneously just before you go in. Tried and tested."

I head straight to the buffet car and get both, taking alternate sips while reading the Star Wars franchise Wikipedia page. All seems simple enough: Jedis, Siths, deadbeat dads, emotional pregnancy, family reconciliation. It's basically a romcom.

With my newfound expertise, I stride confidently to the Arnolfini gallery, ready to wow the judges. I imagine an X Factor-style studio with two minutes to impress the Disney overlords. Instead I'm met with cold, unrelenting rain and a sea of damp teens. Although I arrived more than an hour before auditions were supposed to begin, there are thousands ahead of me.

One hopeful is a martial arts expert who just auditioned to do acrobatics in the JLS tour. Another girl tells me she got the lead role in her school play.

The queue is suffused with a sense of desperation for fame. The hopefuls clutch expensive portraits they got for Christmas or birthdays, internalising talent show catchphrases about this being a "once in a lifetime opportunity".

After two hours, people are damp and desperate. One pretty girl throws her hair over her face. "Do you think they'd let me be Chewbacca?" she asks.

Freezing, I get my new friends to hold my place in the queue while I grab a hot chocolate. In the cafe across the road, a girl stares at her phone. She's waiting for her boyfriend to join her at the audition. "He's worried where this new trilogy will sit within the universe, because it might go against a lot of the stuff in the books." For the next 20 minutes she regales me with how the TV shows and novellas suggest what a new movie might be about. I smile and nod.

When I get back to the queue, spirits have fallen further. The organisers have started walking around with megaphones, telling us we won't be seen, but no one is leaving. Staying in character as a budding acting hopeful, I've started to take the opportunity seriously. A Bristol schoolgirl asks me why I want to audition and without skipping a beat, I reply, "I just want my chance to shine!"

Eventually they block off the queue and ask us to go home. I feel crushed. This was my big shot. I don't care about the lead roles any more – I'd happily take the part of Yoda's jive-talking nephew who plays by his own rules.

In a last-ditch attempt, I run up to someone with a clipboard and beg. "I'm not an actor, I'm a journalist! I'm writing about what it's like to audition! Please just let me have a go." The man looks at me and laughs. "We've already had George Lucas's nephew and someone pretending to faint. Go home, you're not going to be seen."

I am just about to give up hope when I bump into an old friend who works for the security firm hired to police the throng. He says he can sneak me in. I'm not allowed to audition, but I can watch the others have a go.

It's pretty disappointing. Few auditionees are there for longer than 30 seconds. They file in and stand at a desk, a bit like parents' evening at school. They're asked their names, whether they've done acting before, then thanked for their time and sent on their way. Most of the people are gutted when they come out. "I waited five hours for that?" says one confused boy.

But I spot one girl, shyer than the others and incredibly beautiful with long curly hair down to her bottom. She stays longer at the table. What happened? "They want me to come back later," she says meekly. "They've given me a few pages of script to learn. So that's good, I guess," and she walks off with a smile.

I suppose I should be happy for her.