Bug reporting and doco are both very useful, and mostly don't require coding ability. If you find a bug, report it. Use as much detail as you can, ideally with instructions to replicate the bug. "XYZ doesn't work" is useless, "XYZ will crash when used with a invalid file, file to replicate is attached" is gold. Working out exactly what detail is an art, but the more detail you give the Dev, the more chance they have to solve it quickly and easily.

If you struggled to set something up and the documentation wasn't clear, update it. Devs are notoriously bad at writing docs, and most will accept doco PR. (I repeatedly walk people through the setup of my project, because the docs are out of date and I'm too lazy/busy to update them. If someone does this for you, write it down, and see if you can insert it into their docs for them). Anything you do to help new users (which saves the Dev time), is a net positive.

Lastly, coding may seem daunting, but there are tons of resources, and many (but not all) Devs are happy to advise/mentor. Adding small features (button to do X) may be very easy. Some Devs will happily walk you through it if you ask (some may not, depends on the Dev).

https://www.browserstack.com/guide/how-to-write-a-bug-report

https://www.writethedocs.org/guide/writing/beginners-guide-to-docs/