The community would be those who you see at the same café or whatever. Ideally places would have some kind of board or system for people to organize activities. These could be political or just something fun, like a board game night or other things.

As for the kid thing, in many cities the kids will commute to school or other places on their own. We've created a system where that's unsafe in almost all locations in the US, but it isn't required. We have a society of helicopter parents, partially out of necessity because kids can't get anywhere on their own.