Ask Men

Honestly, besides family, everyone I know outside of work, including my partner, came through sobriety-related meetings.

Outside of that resource (and assuming I was normal and not drinking myself to death), I'd say I would need to be volunteering or involved in some cooperative activity.

The friends don't come from the activity, either. Not in sobriety, nor otherwise. The friends come from showing up early and staying late. The people of character are going to be the ones keeping the activity happening for everyone else.

Volunteering

My go-to when I move is to check out board game shops. Generally you meet some pretty great people there. You can also check out "makerspaces" and art galleries if you're interested in crafts.

Mostly what's important is to make the location do some of the filtering for you. Bars aren't great because they cast too wide a net. Think about what niches interest you and try to find a group that's based around it.

Clubs and volunteering. Even at a homeless shelter or similar.

Volunteering is especially powerful because you are implicitly "supposed" to be there. Your presence is already explained and accepted, due to the service mission of the volunteer organization.

Therefore you have already achieved the first step of building friendships: shared experience, and shared time spent. Now that those are established you can step out beyond that to get drinks or pursue a then discovered shared hobby, like cycling or hiking or gaming whatever.

I made some friends through Meetup when it was a more popular website. I think it might still be around. I went to some board game and rpg meetups.

One of my friends met a lot of her friends through the local music scene. Go to shows, talk to people.

Gaming usually.

Late to this thread, but wanted to add to it:

Going out, and going out regularly. Go to places you enjoy, partake in activities that interest you, be consistent about it, and you will meet people. It can be as little as going to the same mom and pop shop every week for a sandwich or coffee, or as big as going out to some kind of club weekly. I actually made a few friends by going to this coffee shop pretty regularly, even hooked up with someone who worked there. Nearby to that same shop was a little occult shop that I liked to frequent and made acquaintances there as well. At one time I was involving myself in a HEMA club and that was super fun and you engaged with a lot of cool people.

Now with that said, there's another part to this. In addition to putting yourself out there to be met, so to say, you also need to know how to converse and listen to other people. Frankly it doesn't matter if you surround yourself with people, because if you are annoying or incapable of holding a conversation, or always come off too strongly, you'll inevitably be ignored.

Find some groups on meetup.com and attend some. It isn't that hard it just takes time. Don't expect to go to 3 or 4 and become friends, depending on the size of the group you may only make friends with one sub group of the main group.

Through other friends and work

Most of the people I've met recently have been via university or work. I've tried going to a board game club as well as taking dance lessons, but there don't really seem to be many of people there my age. For context, I'm in my early twenties, living in northern Europe - and not particularly a fan of going to bars, parties or drinking.