Help Please!!

I lost my virginity to my boyfriend of 5 years , about a year ago. Around the same time, we had sex , we were very rocky and things were just coming to end. We ended the relationship. We had sex only twice. In July, I met this new guy and we automatically clicked, we had sex a couple of times already. He is a little older than me and a little more experienced than me. He likes me to be on top, but I know I'm not the best at it!!! I feel like I can't properly ride him, like I'm not experienced enough. I can tell he gets a little frustrated, and we switch positions quickly. I know he doesn't tell me cause he doesn't want to hurt my feelings or anything.. Does anybody have some advice?? I really like this guy and I want to be able to woo him when we have sex