We’re all trying to adult. It’s not easy! I’d say first of all find an activity you’re comfortable with and join a club / events with that. It could be a drink and draw, a book club, climbing, dance lessons, name it. Try to hang out a few times with the people and get to know them and you’ll see some people share more affinities with yoh than others. From then on it’s just being nice, inviting to get together etc..
There really isn’t one way that works for everyone,but it’s basically about going out and being seen, common interests, being nice to be around, and a lot of luck.