Some ideas below. I might be repeating ideas already mentioned
1. Join a co-ed rec sports team of some sort. We have a social club here targeted at adults with this exact problem (how do you meet people?). They organize a variety of team sport leagues, for a variety of skill levels. In the rec league that I played in most people were ok, but the skill level ranged quite a bit. Most people are there to be social and get some exercise in, so it's slightly competitive due to the format, but overall welcoming to newcomers of all skill levels. I've met a bunch of people and made friends via this method, usually playing indoor or outdoor soccer, but you could do volleyball, softball, basketball, etc.
2. Join a club. If you like to read, join a book club. If you like to hike, look up local groups and join an outdoors group. Clubs like that are usually welcoming even if you've never done the activity before. I joined a University's outdoors club once to do a portgaging trip with my sister and a whole bunch of other people. I wasn't associated with the university at all and they let me join and go on the trip. We spent 3 days/nights canoeing and carrying canoes around in very remote terrain, camping on islands, etc. Had to work together to stay safe, it was a very bonding-like experience. Probably lots of similar activities out there for you to sign up for, depending on where you live.
3. Check online communities for "Meetup" posts. There used to be an annual reddit meetup here and still might exist. Go out, meet random people, see if you click with any of them. Check local forums or social media. People might be out there looking for an extra board game player, extra player for a soccer game, there might be people advertising group hikes to a popular nearby trail.. Do some searches and see what sort of social activities people are advertising.