First time and Nervous plz HELP

Ok so I have been dating my boyfriend for 3 years now and he lives in my town. My parents are allways away at work so I don't know if they are aware that we are even dating. He comes over my house a lot and one night he came over and we were in my room just talking and I was on my laptop doing homework. Then next thing you know we are making out and he is on top of me. And don't get me wrong it was great but I stopped because I knew this was going towards sex. It's not that I don't want to have sex with him because I really really do but I am a virgin and I just did not know what to do so I just kind of laid there and I think that he thinks that I don't want to do "it" with him. But he is experienced and I know that he would make me feel comfortable in just afraid that I'll mess up. And of course we would use protection and be careful but that's not my concern. After that everything was normal but I still felt like he has been waiting for years for this and I ruined the moment. Then the next week I was at his house and we made out again and he managed to get my top off. I was still wearing a bra though. Then He just stopped and asked me if I even wanted to have sex with him and I told him I did but literally just as I said that we heard his dad pull into the driveway so we just ended up watching a movie. Am I doing something wrong I feel like both times I've messed it up. I just want to to be an amazing moment and I feel like I keep ruining the mood. His friends have joked with me before about how I should "give it to him" and how he should "pop my cherry" and I know that it's all fun and games but I am afraid that I will be bad at it or I won't know what to do and he'll not enjoy it. And I know that people allways say that communication and talking about my concerns will help but I have never been one to talk about feeling let alone sex. What should I do?