Drumming

I'm a drummer in training. Been playing drums for my second year with a Grade 3 certificate. It's not really that much.
I cant really help but keep thinking that I'm not ready for anything big yet.
Because of school I dun really get much practice.
That's why my basic is no good.
Due to my inexperience, I cant hear and play songs. That really suck.
I've always wanted to have my own band but I still cant find anyone.
Back to drumming. My friend Zedes invited me to join his band as a drummer.
I wanted to be a vocalist not drummer. Besides my drum skills arent that great.
My teacher says i'll be fine but I still think I'm not ready.
I hope I dun mess up.