Try some of the parks and rec departments for affordable and low commitment classes.

Libraries have or can direct you to book clubs or other clubs that might meet in their library.

Volunteer with an organization; meet people and do some good.

Join a church. There are ones that aren't totally crazy. Mainline protestant or Unitarian generally don't run cults but offer plenty of opportunities for socializing.

Join a community choir (or church choir) or orchestra if you play an instrument.