Plenty of churches don't have "requirements", but that can not be said of all of them. Some are more "organized" than others. If you are a believer, a nice neighborhood church, calvary (maybe) or even baptist (various kinds) are great for community and social interaction. Find one that feels comfortable and don't feel the need to "join". In fact, if they are comfortable with you just attending and participating, that's a good sign. I went to a So. Baptist church that didn't keep track of members or non members. They screened any volunteers, but didn't require "membership" to do anything. I also attended an orthodox church which had a great social hour after church, women's groups, study groups, etc. It was small but active within its walls and out in the community with projects and stuff.
Watch out for the mega churches or tiny churches that are very pastor focused (thats how the WT started). If the majority of their advertising is about their pastor or pastes his face on everything, run.
Episcopalians are nice enough, but some are definitely more into building a community than others are.
Find a church that is useful in its community, not just a place to show up for 45 min on sunday. Some may send out the youth group to invite people to the harvest party or christmas services, but the churches that encourage people to show their faith rather than telling everyone about it are kind of the ones I liked best. they have food banks or a regular rotation of folks who work at one, they have donation boxes for goods in the foyer, they have community notices and allow AA meetings and have support groups or social groups organized. NOT counting hours spent propagandizing.