8 months and worried?

There are a couple things that I have been worried about but I'm a ftm and not sure how anything is supposed to be so...Advice would be wonderful (Please note I will be discussing these with our pediatrician but our appointment isn't for a few weeks so.) Okay so he is 8 months and can roll onto his tummy but not off? We play on his belly all day, so it's not like he isn't getting enough time on his tummy. Second this is, he keeps looking around the room like he has never seen it Before? and then laughing? It kinda freaks me out...Is this normal?? ah I know I sound crazy. 😔 Thanks ladies.