Reiterating the suggestion to take up social hobbies, but also just take up hobbies in general. It gives you interesting things to talk about with other people. For example, I started painting, and talked to other people about it, and now some of them have taken it up and its given us more to talk about and brought us closer together. I find that people like hearing about experiences with hobbies, as its kind of a neutral ground, especially if you're not an expert in it. It also helps if it's a visual hobby like painting where I can show people a couple of pictures on my phone as explanation.