First of all, thanks for the interest! All kinds of contribution, including, but not limited to code, documentation, examples, configuration, issue creating, etc are welcome. Be polite and respectful and follow the code of conduct.
If you think you found a bug, feel free to open an issue. Focused suggestions and requests can also be opened as issues. Before opening a pull request, start an issue or a discussion on the topic, please.
If you found an issue that interests you, comment on that issue what your plans are. If the solution to the issue is clear, you can immediately create a pull request (see below). Otherwise, say what your proposed solution is and wait for a discussion around it.