How do you hit on chicks that you have no clue who they are (in person) >:] >:] >:]?

Ok me and my friends are going to kings island and we are doing a contest on who can get the most girls numbers during while we are there (i know not totaly appropriate but its fun) well i need a way to talk and approach a girl who ive never seen and not seem like a creep lol oh and dont say i dont approve of you doing this CAUSE IM NOT GOING TO LISTEN