Well theres this guy...?

We kind of look at each other from afar. like, we talk a lot but only cuz im friends with his friends. hes rlly nice and funny, and stuff, he says hi to me and is popular. im never gonna see him again cuz were going to different high schools and we never hang out alone or with a group, only in skool. and i dont have his number, but i want it. idk what to do, should i make an excuse to hang out with him?! also im going to his baseball game sunday, what should i say to him!?