Need Advice To Give Good Head

Okay so, my boyfriend always wants me to give him a blowjob. I'd never gave one before. I have gave one to him a couple times and I felt like they were not good but he tells me they're great! He just takes his dick out and asks, which I'm willing too if I had the confidence to know I was good, plus if I knew what I was doing. In this case he was my first so he's my first "official" boyfriend. I've never gave head or a handjob to anyone else besides him. I need tips on how to become more confident in doing it, what should I do with my mouth, how I could become better, make myself want to do it because I fell good about it. Any tips??