I'm someone who wants to contribute to #KDE (mainly #design/#UX). My main challenges so far have been:
My availability is sporadic. I can't guarantee time every week, or even many weeks. I'm really only available for drive by contributions like the Tokodon icon I did when I just happened to see they needed one when I had a weekend off.
As someone with limited time, it's tricky to get up to speed re the technical and design specifications fast enough to contribute.
"Problem" 1 is like mostly everybody in the community. No-one expects volunteers to be available 24/7. Everybody will be cool and grateful for whatever you contribute.