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!
Syncthing.
Connect any two devices’ folders together wirelessly, from anywhere.
Don’t have a server? You don’t need one. Every device is an individual node.
Backup? If you do have a server, offload some of your content and keep on rolling, or set scripts to move files by age.
commenting to remind myself about syncthing for when I can look into it later.