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!
Jellyfin Is completely open source, fully self-hosted, and free. With Plex the software still has to phone home to a central server for authentication and some features are locked behind a paywall.
No streaming software is going to find movies for you (without paying for content they’ve licensed) because that would be a sure fire way to get the project taken down for copyright violation.