Shared hobbies are your best bet. Either find a way to make your existing hobbies social, or get a new hobby you can do with people.

You can also try events at your local bars or meeting people at work, but both of those have serious drawbacks.

And if you are looking for people to date, the vast majority of options you have these days are online. You can try hooking up with strangers at a bar or meeting someone while engaging in a social activity, but statistically a tiny percentage of couple meet that way these days.