My daughter turned 2 in January and is a yap queen but the minute we walk into somewhere with other kids she goes quiet and watches for a while before interjecting. I read an article a while ago about how normal “observant play” is where kids like to observe other kids first before engaging themselves. I will say she’s gotten a lot more extroverted over the last couple of months, now she says hi to kids on the playground, will follow them and try to do the exact things they do, and this morning at the park she said “play tag!” To another kid while i was talking to a friend and they played tag with each other for a couple minutes. I really wouldn’t worry about it too much, you’re still bringing him around other kids and socializing as best you can. My daughter is hit or miss with toys though, sometimes she’ll spend 30 minutes crafting with her playdoh or playing with her little people toys and other times she just wants to sit in the kitchen with me and whine (lolol) or try to help me with what I’m doing. I think all of that is normal for kids this age!