Go start a hobby you've always been intrigued in but never actually done. Go and give a few hobbies a try and see if anything sticks. If there are people around, just say "hey, do you have any advice for beginners?".and that could get the ball rolling.

Or if you're interested in cars/bikes, find a local meet. You don't have to own one to turn up to most of them, lots of people go just to have a nosey at what's there and when you get talking to the owners of the vehicles, you'll find you can't actually shut them up and they'll talk to you for literal hours if you let them.

The thing is, you've got to actually put yourself into situations where you could be social. That's the hard part.

There's lots to do, it's just finding the effort and sometimes money to go and do it and then also make yourself socially available whilst potentially being nervous during a new activity.

Just pick something and make it your goal to do it at least once to give it a try, and have another goal of actually talking to someone whilst you're there. If it goes nowhere with either the new hobby or social interaction, at least you tried, and the more you try the more practice you'll have and the easier it'll become just walking up to essentially random people and starting a convo.