Depends on how you want to contribute
Testers for PRs are always needed. Currently, in the CMS there are about 380 open PR's. Of those only about 23 have received testing and the RTC tag for successful tests.
There are also about 488 open issues not addressed by a PR in the CMS yet. so if you have the knowhow and time to figure out how to fix things, that is also needed.
Testing Instructions
Reading and cleaning up the Documentation is always a big project and is a good place to learn from and help.
You can always find more opportunities help on the volunteers site
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.
With that being said, welcome to the community; and thanks for being willing to contribute.