A dance is coming up and I plan to ask her to dance. But what kind of pick up line should i use?
You come up to her (if she is always with friends), you say, "Hey, [name], could I borrow you for a second?" And then she says "Yes," you go a little bit to the side and you say, "There is a school dance on Thursday, would you like to go with me? Cool. Pick you up at 8." Or you could call her and say the same thing.
And where do i look when I'm dancing? in her eyes or wut?
For fast dances:
Ideally in the eye. If you are too shy to look straight in the eye, focus on the center of her forehead.
For slow dances it's not a problem because her head will be in your shoulder/neck.
And what do i say after it?
You say, "[name], thank you for dance." If you want to keep dating her, you say "I will call you tomorrow."