I leave by the emergency exit.

First I would remember that there are surveillance cameras and probably security somewhere in the building. I'd be avoiding that stuff if I'm gonna have any kind of mysterious adventure. I suppose if this is the kinda party I think is a good time... I would set about creating an access so that I can come back later if I want. I actually did a lot of sneaking around in places I wasn't supposed to be as a kid... not that this is particularly abnormal... but I had a particular fixation on it. Not for any destructive purpose, just for being in places that were normally full of people... when they were empty... or "behind the scenes" of such places... Behind the movie screen... under the school... in the attic of the library... that kinda stuff. It's very unlikely that I couldn't figure out an egress unless we are orbiting earth or something. I imagine the author is more curious to know what kinda mischief you might get up to, rather than how you would escape. I like the feeling of being in uncommon places. I'd probably spend my time checking out all those various nooks and crannies, looking for secrets. In other words... lurking. I'd make a great monster.

Find some roller skates. Wheeeeee!

Cal l911

Break into the jewellers and rob it blind! I have no morals and I could hide a few £100,000s worth of jewels down my bra!

Go to Victoria Secrets and roll around in silk negligees whilst admiring their photos.

Go find the candy store and totally pig out.

kill Zombies

Happened to a friend of mine, he spent a few hours using the gym equipment, then had a sleep, finally he hacked the phone socket and called his father to contact the security firm he worked for, (yep, he was the security guard and locked himself in) they didnt hurry and I think he was left there for another 5 hours.

Sleep.

Take off all my clothes

Sleep. ?