Normal rolling over/sitting up age?

Lexie

My baby boy is 2 months old and hasn’t rolled over yet, but he can hold his own head up pretty well while I’m supporting him and I feel like he’s a strong boy! I’m a first time mom, and was wondering about what age is it normal for a baby to start rolling and sitting up? I figured it would be about this time or 3 months. I’m afraid I’m holding him back from learning to roll b/c he never wants to lay flat on his back or be on his stomach unless he’s sleeping on me or his dad. I have him sleep propped up in a boppy pillow in the bed with me. I know many parents and doctors would advise against this but it’s literally the only way he seems comfortable or wants to sleep. I play with him on the bed and talk to him. I read to him and am with him literally 24/7. I just don’t want to hold him back from learning what he should be. If anyone could give me some advice or simply ease my mind it would be greatly appreciated! ☺️