Also, dont get too worked up about it before hand, or go at it with expectations, otherwise you may be too stressed to enjoy it. If he knows its your first time, then he'll probably take it slow.

Don't be scared, as said to instruct him, verbally or phsycially,but don't critise him. If he does something you like, encourage that. If he does something you don't like, be constructive like, 'Its a bit sore here, but I really like what you were doing just before'. Or if you don't want to actually say anything, because you feel weird doing it or what not, you can use noises. Like when he gets a spot you like, moan a little. It'd send the same message as a compliment.

At the end of the day, he wants to get you off, and he may be nervous too, and his expectations are on himself, more than you. Let him lead it if he's done it before, and you are unsure.

If the feeling hits you, making out is ok, not making out is also ok. Be relaxed, and aim to have fun. Remember, it doesn't have to be perfect, in fact, it rarely is. Being light hearted (but not comical), can really help break the awkwardness. It's meant to be fun and enjoyable. Not serious and too the point.

And if you feeling like you are reacting, maybe with heavy breathing, or even moans, don't be scared to express that. It's a real turn on when you are fingering someone and they are reacting, it tells you that you are doing it right.

The guy will hopefully explore you down there, as well as put his fingers inside of you. If he doesn't automatically, encourage him to massage around first, such as exploring the clitoris, etc. Just poking a hole (mind the bluntness), isn't going to be as enjoyable.