Should i give him a bj?

In 15 and I have a boyfriend who wants me to give him a blow job and I haven't done it because I'm not sure if I should. I know he wouldn't tell people and I'm not scared and it's not like I'm not ready. I'm just nervous if I don't do it right or if it's the wrong thing to do. We have not had sex but we have done other things excluding blow jobs.