How do you get a random guys number?

I'm going to my cabin at 4th of july and if I see a hot guy there I wanna know how to get his number without just asking him. (I'm a preteen.) I would say I'm somewhat pretty. Andd I really don't care if I'm too young. Just answer the fricken question. is there any gestures I can send to him to come up to me? Or any signs with my hands? Idk. Haha thanks for the advice! But I don't wanna just go up to him and say hey wuts ur number I want HIM to do that :) I'm kinda shy