Couple of questions on my 6 month old

Tummy time? I do it ever day and he doesn’t roll over he screams and screams. Yes he has rolled over once or twice but usually doesn’t. He holds him self up well while on his belly. He sits up perfect, likes to stand while holding his arms. Anyone else experience this?

Also Dr said he should be saying words like dada mama and baba. I have thought I heard it but don’t yet. He makes plenty of other sounds. How did you get your child to start making those sounds?

Next question with baby food. I make his food. I made him peas mixed with corn and he doesn’t seem to like it. Any suggestions on what to mix with greens to help him like veggies and not just fruit.

Thank you all.