Then being supportive on the forums and other support channels is probably the best you could do.
That is, unless you want to spend a lot more time on Citra (like a lot of our top contributors). The idea below is something a non-developer could do to contribute, but it takes a lot of time.
If you want to learn about the emu development and also contributing at the same time, I’d suggest getting on IRC, reading the PRs on github and try to write blog posts / progress reports about it for the official citra-emu.org blog.
It would involve talking to developers to clarify things, follow ongoing discussions and put things in layman terms. Once you’d finish an article you’d ask the respective developers for feedback so we don’t publish anything wrong.
We also have a handful of other people who are willing to review and help writing - it’s just that nobody is motivated enough to write a full article on their own
There are probably other, similar things you could do: Check if old issues still exist and create new bug reports if something has changed (regression testing / bisecting). You don’t have to be a developer for that, but a technical understanding is necessary. You must also learn how to use git and at least how to compile / build your own Citra.
pcmaker / John Godgames is an excellent example who started out as a novice user creating emulator videos, who has then become one of our most helpful testers / regression tester. He never contributed code, but still learned to think like a developer and uses the same tools to create good bug reports.
Anyhow, find something you’d like to do and just try to push the project forward.