Give it a shot. You don't know if you don't try.
I've been crushing to this guy for 3-4 years and ive never talk to him even once but i sure he know that i like him and now I've have his number should i message him first because this is my last chance because this is my senior year?
Why haven't you spoken to him in all this time? I think it might a little creepy to just text him out of the blue if you never spoke. It's really how you want to handle it though ...
If you've never talked to him ... How did you get his number?
If somebody called me out of the blue, that I never talked to before ... That's what I would wonder. And I damn sure wouldn't answer the call or text, from some "stalker" who got my number through unknown means.