I need good sex

So im 16 and I’ve had sex with my man 4 or 5 times now and it’s just not all that great, idk how to make it better and he always tries to make me do the same position every time. I also think we need some lube but idk how to tell him anyone know any good positions and whatnot? I’m thinking next time we are going to do it to like just google some as a ‘joke’ to try??