You have any MALE dance friends? I would suggest learning how to do a dip, but honestly it doesn't matter. DO NOT ask her to teach you how to dance. I hate it when girls ask me how to do a step on a social dance floor. Sometimes I just want to talk to them, move with the music, and i don't care whether they are a dancer or not. Do this: when the music starts, say "let's dance" and pull her on the floor. It is ok if you are terrible, it can even be funny (just get into it). When you think the time is right, pull her tight and kiss her. She'll think you're the best dancer in the world. Good luck.