I live in a neighborhood with quite a few gay neighbors. Most of them are couples.
You could always give them a housewarming gift.
My neighborhood has community events all year long so I eventually meet most of the neighbors that way.
I have an HOA as well. Our HOA created a sub board to create events within the HOA budget: Social Committee. It is a great way to build a community, get to know the neighbors, inform residents, etc. We have a Halloween Scavenger Haunt, Holiday (december), Caroling, Spring Festival, and movie nights in the park. And we add more events over time. Some of the neighbors, for example, want to put together a dog show. That would bring out the gay people..lol..."Best In Show"