I'm helping a bit with Debian. If you want to do this and you can't help much with debugging, there is still plenty to do. You can improve documentation and you can triage bugs.
Triage is a medical term. In an emergency, such as a plane crash, many people are hurt. Split decisions must be made about who needs treatment now, and how can wait, and perhaps even who is beyond help. This is the triage.
When applied to bugs, it means prioritising them according to how serious they are, and how hard they are to fix.