Looking at my GitHub history, my first PR was opened against XBMC project, which is now known as Kodi, at 26th November 2016. I was just trying to fix something that annoyed me at that time (missing support for Beebox IR controller).
Regarding Fedora, my first PR happened on 6th August 2018, when I started working on release-monitoring.org. I was still learning the ropes of that project, but I was able to enhance the default regex being used by Anitya at that time. 