Guy advice needed! how to say hi to crush...?

So I like this guy who used to be in my cl. but everytime i see him i cant say hi. i open my mouth but nothin comes out. and sometimes wen im with my friends one of them say hi and they say he said hi back. but i want to say it so badly but its hard D: this year im like the shy bookworm girl. and hes never said hi once. even though he sees me like EVERYDAY. and last year i used to be the oppposite of shy and i picked on him. now he is all like kinda dorky cool guy who hangs out with kinda ghetto guys. (even though he'll never say be ghetto XD) so how do i say hi and what if he doesnt say hi back?! (i kinda hav more information on my other question) i kinda feel like he likes but i kinda feel like i dont. and we got seperated from cles. and at school we r doin this thing where we get to send candy to someone or ourselves and we could put anonymous but ppl from my cl r doin it so im kinda worried they would look and ask ppl i know if they know who it is and theres three guys who were in my cl last year that r in my cl now. and I HAV NO IDEA WHAT I SHOULD DO!!!!!!! DX