Texted my crush if we could hang out he said no cause of hw butI feel I scared him away cause he never texts 1st but while walking class he saw me and his face lit up when he saw me he nodded his head and kinda smirked and said "sup" like he was cool?

I've had a very similar problem. He's flirty around you but fails to communicate over texting. Sometimes guys get nervous too, which is why he never suggested another time. However if you were very general about when your hangout would be and he still managed to say he was busy, this might imply that he doesn't like you and just doesn't know how to tell you. But what it seems to me is that he was genuinely busy and is perhaps just a bad communicator. By making an effort to get your attention in school, says something. I would text him again and see when he's free and try again.