Parties are also great. My current relationship was the result of going to a School of Public Health crêpe party.
Everyone who starts learning the Waltz or ChaCha (or Swing, or Tango) is appalling at it. And it's pretty liberating to be in a group of people all of whom are happy klutzes.
At my (pretty tech-centric) university, the dance club had over 2000 members : the key selling point for the guys being 'girls like to dance'. And learning steps together has a logic component (so it's satisfying to see yourself getting better), but also a huge WTF component - which takes everyone out of their comfort zone in a good way.
Don't worry about the excellent dancers showing off : they'll be taking other classes.
However, the basic initial win for the OP is to get out of the house, and have a blast learning something with a bunch of other people. The aim doesn't have to be to get good - it's a major step just to turn up. I was just trying to suggest that every beginner will be in much the same boat. IMHO, learning to dance is a much easier social activity than 'going to parties', for instance.
BTW, you might find going straight from coding all day to dance class an interesting experience mentally. :P