I’ll start by plugging Harvard’s free courses catalog as well as Udemy
Edit: Gonna add 2 more I remembered-
Blender - I wish I had more time to learn it, but I did start the infamous “Donut Tutorial” once!
Watch Cartoons Online - Lots of good older stuff!
LMMS - free and open source garage band. It’s a little weird on how you do a song, but it’s pretty great.
Tips: Look at Beats and Baselines Editor and Piano Roll Editor first to probably get you where you want to be.
And if you need some free virtual instruments, Plugins4Free and Vital.
Other free, though not FOSS DAWs are Reaper and Waveform.