As a 36 year old that recently moved yet again to a new city (the third time in my adult life), I've had decent luck joining recreational sports leagues. Lots of leagues will have options to sign up as a "free agent", which usually means you'll get placed on a team with other free agents, which tend to be others in the same boat of trying to meet new people. If you aren't necessarily the athletic type, bowling and kickball are pretty good options. I've found that most of these leagues (especially if you sign up for the novice/recreational level) are NOT very competitive, and most people are just out to have fun, meet friends, possibly have some drinks, etc.