I've tried a number of things over the years. Sailing, climbing, running, board game meet ups, drinking meetups, golf, crossfit, curling, probably some others I'm not thinking of. Just pick something and see if it sounds interesting to you and give it a go. My big advice is to avoid shelling out on gear. Rent or just get some beginner stuff. Most of these things didn't stick, but I'm a runner and a climber and oddly I've had some great platonic connections through crossfit as well.

Hey, so, I live in a city but visit my parents in the suburbs once or twice a year and at it did take some work, but there are certainly third spaces. After trying a few, I found some very comfy cafes to work out of, I prefer it since my parents can be a bit distracting. Also one cafe I really like is in a 'town center' which does also have a gym. So while you may not be in a city, see if there might be any pockets of walkability you can park at and enjoy the day on your feet.

Maybe moving house to a denser and more walkable location is a feasible option?

Yes moving is a pita, but you can’t fix an urban landscape that is not working for you.

In my opinion if you're searching for a hobby it's best to be a bit more methodical about it. Usually the way to get into hobbies is that a friend or acquaintance pulls you into it (either by talking about the hobby energetically or directly showcasing it) and going at it from the other end isn't really easy per se in my experience.

But yeah, it's more than doable. First things first take a piece of paper (or do it digitally) and divide it into 2 halves, indoor and outdoor, then further divide those 2 halves into solo and group. At this point it doesn't make sense to take financial constraints into account, that's up to it at the end as a determining factor if you want to start a hobby from your "short list".

So after you've done the above take a week to fill the paper with stuff like "Tabletop RPGs" which goes into indoor/group, or "nature photography" which goes into outdoor/solo and I hope you get the jist. I'm sure you know where to file embroidery for example.

You can continue to add hobbies as a hobby too for a little bit, call it hobby watching and searching, it's still a pastime. Now here's another important part, you have to decide your motivation for start a hobby (not a specific hobby but a new hobby). Some people try and do hobbies because they feel they're forced to if they want to appear interesting to their peers, sometimes you just want to fill a hole or fill time so you can't stop and think about that hole. In emotionally adjusted individuals supposedly you can pick a hobby for the fun of it and that's enough. Basically do a bit of soul searching so that you can decide if you gravitate towards a outdoor hobby with a group of people (because the hobby itself doesn't matter that much but you crave connection which is completely fine and that's why some old people go to church).

I could go on but thanks for reading my TED talk and I really hope you find what you are looking for, either a hobby or something else.

EDIT: I completely forgot! You might also try finding a charity in your area or volunteer organization and volunteer your time. Maybe you need a higher calling or a mission to keep you going instead of a hobby. Food for thought. Though do be careful if you take that route because some NGOs tend to attract people who are energy vampires to say the least. Try your local library too if you have one and see if they run some programs you can participate in or help with.

Can you move to a city? This is what most people I know in this situation do. Though I had a great time getting a car and taking myself out for hikes, sauna / spa days, activities and parties in the east bay near SF. Great place for practicing being alone. I had to think about it like dating myself - where would I have taken a date for fun? Try a bunch of things and see what sticks and remember you can appreciate moments by yourself with this mindset and it's like 80% as good.

How about the library? A lot of suburbs have libraries

Try out a lot of different things and see what sticks. You will hate some things and love others. Computer gaming is fun, but is more of what you are already doing, because you are on a computer alone. Meeting in person is very important.

I've surprised myself by finding that I really enjoy knitting for example. I don't fit the usual profile at all. But I tried it and enjoyed it. It may not be for you, but something else might be. Some people love hanging off rocks on ropes, and some love D&D — neither of these are my things but it gives you an idea of the range of things out there.