There are plenty of non-church choirs and music groups. That is, if you live in a decent-sized city. If you have some musical ability, it's a great way to mingle.

Community theater and improv groups are other possibilities. Sometimes they are looking for volunteers to do a variety of jobs. It's not all about performing.

I wasn't suggesting you fake being religious just to attend a church. I'm an atheist myself, but I was raised in the church. The only things I miss about it are the socializing and some of the music. I thought if you were already religious, you could find a larger church. (I got flirted with a lot in church.)

And I'll point out that some religions like Bhudism and New Age spiritualism can be more like philosophy than religion, depending on the group. There's absolutely nothing wrong with attending out of curiosity. They expect a few "seekers" to visit.

There are also things like adult education. Cooking classes, dance classes, and the like. Also book reading clubs. Not ideal, but better than sitting at home.

Good luck. I know it's highly challenging in these cynical times we live in.