Depends on how you want to contribute, and is you want to contribute to the Framework
and/or the CMS
Testers for PRs are always needed. Currently, in the CMS
there are about 381 open PR's
. Of those only about 32 have received testing and the RTC tag
for successful tests.
Reading and cleaning up the Documentation is always a big project and is a good place to learn from and help.
As Brian mentioned You can always find more opportunities help on the volunteers' sitehttps://volunteers.joomla.org/
PR = pull request, these are proposed code fixes
RTC = Ready to commit, these are patches that have been tested and could make it into a future version.
Each of the packages in Framework
have their own set of open issues and PRs needing testing
I'm currently asking for help in completing
and validating the upcoming alpha Code Standards implementation with PHPCS 2.9.x and PHPCS 3.1.x so developers can have access to the code style autofixers. https://github.com/joomla/coding-standards/
Additionally, there is lots of activity and help needed in Testing Joomla! 3.7.0 Alpha 1 for release candidate status, completing the 3.9 and 4.0 versions of Joomla. We also have need for people to help with improving the unit testing code coverage.
There is also a mailing group specific to the CMS development https://groups.google.com/forum/#!forum/joomla-dev-cms
With that being said, welcome to the community; and thanks for being willing to contribute.