What do you ask a girl when she asks you what you want to know about her?

Well, what do you want to know? If you absolutely can't think of anything, go with questions about her favorite music if you're feeling safe. If you want to have a fun conversation, ask what the funniest thing that ever happened to her was. Or ask what's the most embarrassing thing that's ever happened to her. Have fun with it and start an enjoyable conversation!