This document covers contributing to the codebase of the CMS but the community site has plenty of inspiration for other ways to get involved.
If you don't feel you'd like to make code changes here, you can visit our documentation repository and use your experience to contribute to making the docs we have, even better.
We also encourage community members to feel free to comment on others' pull requests and issues - the expertise we have is not limited to the Core Collaborators and HQ. So, if you see something on the issue tracker or pull requests you feel you can add to, please don't be shy.