Okay, you've found your project, now what? You might be tempted to start making changes right away, but if there are a lot of people on the project, you probably don't want to do that. Most large projects, open sourced or not, have some guidelines for contributors. Project Porcupine has a few things to note, depending on if you are doing artwork or code. Code has its instructions in the Contributing.md file. Code has style guidelines that are enforced, along with unit tests that must be passed, for any change to be accepted. It also includes instructions on how to get your change in to the main baseline, which I won't rehash.
There are other ways to contribute. Project Porcupine is hosted on GitHub. Github has an Issues page. You can test the latest build, and find and report bugs. Report bugs by opening a new issue. Issues don't require any programming knowledge! These are open for a large variety of issues, including game design, bugs, proposed new features, project management style guidelines, and more! Feel free to contribute to them, or open your own.
You can also test proposed Pull Requests (PRs). A pull request is a set of changes that someone is proposing to include in the main build. The wiki has instructions for how to do so, so I won't re-hash. Look at a PR, test it per the instructions. If it works good, or doesn't, let everyone know by adding a comment to the PR.
These projects can take a long time, but can teach you basic project management. I've learned a lot about managing large software projects, many cool programming tricks, and principals of game design, all in a matter of a few weeks of working on the project. I hope to see you contributing to projects soon, be it this one or others!
Ben Pearson is the author of the Amateur Radio and other technology blog KD7UIY and developer of Games and Apps at Google Play pearsonartphoto, where he plans to publish some of the games created by inspiration of gamedev.tv. He is currently working on a Sea Trading game, which you can subscribe to updates at Old Ham Media. He has been a programmer since a young age, although only recently is learning programming with game engines. He has completed the the Complete Unity Developer Course and the Procedural Generation courses, and is working through the Complete Blender Developer Course, Unity Developer Certification Course, and Unity Game Physics courses. He is hoping to soon start Unreal Courses soon. Follow him on Twitter @KD7UIY.