So Nervous!

So I'm 17 years old. Gonna turn 18 in October. I'm talking to this guy right now and I finally worked up the courage tonight to tell him I want to suck his dick. For the past hour he and I have been planning how we're gonna get this done. Anyways, the homecoming dance is coming up soon and he's not going but he wants to pick me up afterwards so I can give him road head on the way to a restaurant. And I'm telling my mom that a few other friends will be there as well so she feels better about it and will actually let me go. (She already suspects that there's something going on but i keep telling her that there isn't because its not her business) anyways. I just need some advice on how to go about this and what to do because I've never done anything sexual before and I'm kind of nervous! Anything will be appreciated.