First check if anything you're using is on github, accepts contributions and has some open issues that looks simple to solve, or if theres some new feature u want to propose, then follow their steps for contributing.
Don't go looking for issues on stuff u don't use or don't plan to use, or at least some friend/family uses, it'll feel like a chore and you will have to spend a lot of time figuring out how stuff is supposed to be used what anything does and why...
Nah, those aren't Goodenough.