You are only limited by your imagination!
There are many options including online dating, the gym, hobbie classes, joining groups such as "Parents Without Partners", traveling, participating in local activities, and enjoying life in general. Being positive and outgoing attracts people. Imagine the type of person you want to meet, the type of things they'd enjoy, where they would live, shop, the type of occupation and so forth. Once you have been "in their shoes" the next step is to be in all of those places where you imagined they would be. In order to meet someoone you have to be where they are!