First gay hookup, what should I expect?

Met a guy off OKC, was kind of surprised because I listed myself as straight, and he still liked my profile. Decided that I've been wanting to try new things for a while, so I was thinking about giving it a chance. He plans to just give me roadhead for a hookup, but also asked if I have condoms, so I'm not sure if he wants to try full out anal sex. In case it comes up, I would most likely say no, but in the case that I find myself enjoying the moment, what should I do to prepare in case I'm the bottom or if he wants me to be the top? I know this is kind of a jumble of text... But I'm kind of anxious.