mike_h has some good advice, deconstructing other people's songs is a great way to learn Renoise. The forum was pretty friendly when I was active, and people post examples frequently, so that's a great resource.
I also recommend learning the keyboard shortcuts like the back of your hand. It really helps with keeping in flow and is one of the biggest advantages of the tracker interface.
Old mod creator here. (B00MER/kosmic aka kfmf) Most of the fun that disappeared with mp3s is such an ability to deconstruct another's work because of the similar appreciation for the same art.
I would spend hours upon hours pouring over any of my favorite tracker artists like keith303, purple motion, lizard king & c.c.catch, etc. even ended up flunking out of high school because the demo scene art subculture was really alluring to my younger self, as it just made sense to me & was something I thoroughly enjoyed.
To this day I can typically listen to any song and see the tracks, channels & notes in some regard. If you have no formal background in music but have an itch you can't scratch, explore trackers or even the more popular DAWs like Ableton. There's not much rules, so just have fun.
"Even if I'm the last person out there doing it, it's a quiet pursuit. It's, a personal pursuit & it's something that helps me get up in the morning." -dj shadow
Old creator here too. I miss the Fast Tracker days. I went so far as to have two Pentium II computers both running Fast Tracker, using MIDI clock sync between them then deconstructing source music from all those favorite tracker artists, playing partial multiple songs at once. It never got old, always fresh each time.
Then MP3s came out and the whole concept of trading source music for live remixing was lost. Another amazing thing was how compressed they were. I once put my favorite 1700 S3M/XM/IT/etc songs onto a single CDROM! That in itself is wild to think.
I also recommend learning the keyboard shortcuts like the back of your hand. It really helps with keeping in flow and is one of the biggest advantages of the tracker interface.