Pick something you use regularly that's open source, and check out that. Something you have familiarity with is going to be a lot easier to contribute to, beca

Pick something you use regularly that's open source, and check out that. Something you have familiarity with is going to be a lot easier to contribute to, because you will notice bugs, or think up a feature. Like I added an option to a vim plugin I was using that was open source, and then sent a pull request because I thought someone else might like it, and it got accepted. Another good thing to do is to write documentation for code before you contribute to it. Plenty of code lacks clear documentation, and having to read the code and understand it will help you contribute later.