In the (anarchist) union I‘m in, we have neighborly get-togethers every month, where we talk about our life & work & just eat some food together. But it‘s really nice, there are people of different ages & different professions, so a lot of different perspectives.

Sometimes you build community by simply being the first to organize something -- anything.

Simple example: it's really hard to find a D&D game to join sometimes. But if you start a new table (and offer to DM), then you're flooded with prospective players immediately.

The whole "if you build it, they will come" angle works provided you're willing to put the effort in.