I was a part of a non religious “atheist church” group like this until it turned into a polyamorous sex cult and then some people got jealous and metooed the leader, and one of the lead organizers became homeless because of severe mental health issues.
I actually find this experience super interesting. I didn't know things like that existed and looked skimmed the article for Sunday Assembly to learn more: https://en.wikipedia.org/wiki/Sunday_Assembly
Unitarian ones are nice. I’m not very religious but went on sundays for a while just as something to do/an excuse to get out of the house. They don’t care what you believe, and just exist to celebrate each other.