When you find a bug in an open source project, you know exactly the change you want to make. Other times you just want to find a way to contribute. Either way, you’ll need to know how the project maintainers want to run the project and work with them to come up with an implementation for the fix/feature. And if you don't even know what project to start contributing to, check out this blogpost for inspiration on how to identify a good project to contribute to.
The link mentioned to see recommended projects to contribute to is dead, but I found it here: https://blog.kentcdodds.com/what-open-source-project-should-i-contribute-to-7d50ecfe1cb4
What is padleft function :)?