What should a 14 year old girl do on a Saturday night?

Go to a movie with some trusted friends, stuff like that. Be careful with parties and stuff til you're a bit older, I was just starting to get loose at that age and it's pretty dumb to neglect school etc so early. Once you're maybe 16-18 you can buy anything without people ripping you off, and it will be easier to find booze without being hassled. Take care of yourself though.