During Spring Break I met a friend of a friend, and I really liked her. After some random flirting, I held her hand during a movie. Nothing big, but normally I would have trouble doing this. For some reason I just did it without thinking. She and some other people came over to chill at my house later during break, and I didn't make any moves. Now she's flirting hella with my best friend who just starting dating her best friend (so there's no chance for them).

I told her I like her, but she should tell me if she doesn't like me back so I'm not wasting my time. All she said was that we should hang out more. Now I'm very confused about what's happening. One of her best friends told me that she loves to flirt and only agrees to date people because she either pities them, or is interested in them for a short time.

She doesn't have any clases with me, so I never have a really good chance to talk to her. I think I might have a chance with her, but she's so confusing. What should I do?

You should forget about it and move on. Stupid girls like that are not worth your time or your thoughts.
Trust me.
I don't care how hot she is.

if this girl only dates guys that are not you your probably not going to get a date. forget her.