How to find friends

My boyfriend and I broke up after a very long time together. He has moved out. I have graduated from college and I have a job that I love, but I'm in a city that I didn't want to be in and my family lives far away. I am wanting to stay so I can keep my wonderful job, but I don't know how to make new friends. I'm in my early twenties and work at a place where everyone is significantly older. The town is smaller than what I'm used to, so there isn't a ton of stuff to do. Unfortunately, my ex boyfriend will be in the same town. What do I do to make friends?