I've only had sex while on the bottom, or when the guy was in control, plus I haven't been having sex for that long, so penetration takes a little while. Basically, I'm scared I'll tense up and won't be able to get it in or know how to move?
Try moving to another position after he's already inside you. That way you should be relaxed and lubricated enough to "take over". Enjoy
Yeah, thats a good idea TheGhost. Also, bare in mind when you're on top, he can't make any mistakes and hurt ya. Once you slide his cock in, just move around, take your time and you'll get into it, I'm positive.