You want to look for some kind of social hobby that naturally attracts a wide range of people, both men and women, is in person, and makes you happy regardless of whether you're actually meeting people.

Certain sports qualify. Volunteer groups can qualify. Some hobbies work.

For sports today the rock climbing community is very inclusive and the sport naturally causes people to get to know each other since you can't climb with ropes in most places without pairing up with someone. The whole gym culture of rock climbing didn't really exist yet when I was in my early 20s.