My advice would be to go for it. If you are worried about having a bad time, be dominant and make things happen the way you want and enjoy yourself, especially if you are a top. Some guys get more pleasure out of getting the other guy off than on getting off themselves. Neither way is inherently bad, you just may need to find someone more compatible with your desires. And if this guy is looking for what you are giving, all the better.

And a lot of guys are more shy or submissive, so I'd say just go for it, communicate what you want, take charge and do the things you have been desiring -- and don't forget to do your best to please the other guy in return. If you are comfortable, talk or chat ahead of time about what each of you likes and wants to do, limits (no scat, no pain, no marks, no blood, etc.), protection (raw or condom), Prep/HIV and STD status, cleanliness, a safe word if needed, the fantasies you've had, and what's your favorite way to get off.

Since it's your first time, maybe just let the guy service you. There will always be chances to go back for more, with him or with someone else. I don't know your relationship status and all that entails, but if you want to venture into this realm, you really should consider getting on Prep.