At school there were clubs where I could find others with the same interests and make friends that way. After leaving all this behind, I'm a bit lost as to how people make friends post university. I think it gets exponentially harder to make friends as you age. When you're a little kid, anyone can be your friend but as an adult you have all these other filters you think about when trying to make an informed decision about friendship.
How about joining a local gym, and meeting people there? I moved to a new town recently, and after joining a gym, I met people who I now train with, and see regularly and also go out now and again with them. Most people in my gym are friendly, you just need to be proactive and say hi and start a conversation, some people will reciprocate, and some won't, you just need to take chance.