Blowjobs..

OK, me and my boyfriend are at the point of having sex soon, I'm really comfortable with him and despite him not being a virgin and with me being one, he's been really patient. See I'm all fine with that but he's mentioned a few times how amazing blow jobs are. We've never done anything more than kiss so I have no idea. I'm scared that I'm gunna panic or hurt him or being really awkward when attempting to give him a blow job. I also have a really bad gag reflex which I am really worried about. Despite me really not wanting to do it, I want to at the same time, especially because I know he will love it plus he's planning on giving me oral... If you could give me any tips I would really appreciate it.