[felixnm]

Expose yourself to new people and different situations:

Take a class at a community college or maybe teach a class or become a substitute teacher at a local high school or grade school.

Join a sports club (like others have mentioned here) - Cross-fit, Jiu-jitsu, Krav-Maga, running, cycling.

Go to your library and check out the bulletin board - usually there are club notices or other events posted.

Get a part-time job that involves a lot of interaction - Walmart, McDonald's, chair-lift operator at a ski resort.

Volunteer at a food repository or at a charity like Feed My Starving Children or assist at a retirement community. For volunteering, in Chicago we have https://www.chicagocares.org. There might be something similar in your city.