How to learn to socialize

I (28M) have been alone all of my adult life, but only recently did I realize I’m lonely with the help of my therapist. How can I learn to socialize and make friends?

I had friends when I was back in school, but after that I wasn’t forced to interact with other people so I avoided that. I have a lot of anxiety about meeting people, remembering their names, getting rejected, etc. I know I can’t overcome those fears without getting some real world experience, so that’s what I’m trying to do.

The trouble is I have no idea how. I work remotely so so face-to-face time with my coworkers. I know people in shows hang out at bars and coffee shops, but I don’t know how realistic that is. What would you guys recommend me do as a start?