I really need some good tips/ advice please!!?

okay so me and my boyfriend ( were both 17) we've been dating for almost 5 months and were both kinda prude and the farthest we have gone is making out. and we both want to go farther than that, like a bj or a hj or both!(; haha, and were both really comfortable with eachother (we were bestfriends for several years before we started dating) and were supposed to hang out tomorrow night (his parents will be gone until Saturday) so we'll probably just play video games like we always do. I was just wondering what's a good way to go down on him (like start making out and then giving him a bj/hj) I want to surprise him and I don't really know how to start something like that because he's always started it. thankyou so much!! :D