1 - I host a game night once a week. We play Magic the Gathering. Though the group is quite small now (4-6 people) it was quite large pre-pandemic (~20 people). I just asked around at work and the neighborhood if anyone was interested and just sent out a text every week to those who said they were interested.

2 - Monthly board game night. Very similar to #1, but I mention it because it's much less formal. There's a small group of neighbors in my little neighborhood. Once a month or so one of us will text the group and say "Who's up to board games? I can do Wed or Thurs". Usually have 3-5 people actually show up so far. But it's been fun.

3 - "Knit Night". My wife recently joined a group of people who like to do more ... traditional style crafting. Mostly crocheting and knitting. Though there's a little bit of quilting. And sometimes people show up and draw. One time one person did a stained glass kit. But they just get together every other week, take turns hosting.

4 - Band. My wife joined a local for-adults band. A former band-instructor from a local highschool formed it. They do performances in the community 4 or 5 times a year. Apparently these kinds of bands are pretty common. Probably could ask a local conductor at a highschool, middle school, or community college if they know of one locally.