I’m worried I won’t be good

I’ve had sex before but not alot of experience. Neither of us had a good outcome or came. I don’t know if it was me that made the sex bad/boring or him or both? I’m talking to this guy for a while and we both want to have sex but I’m worried it won’t be good and that he’ll find me boring. Is it me? Something I need to do to make it better or just go with it?