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!
Technically not free, but because so many people think it is it’s a great poster child for proper use of tax dollars and socialist programs. Libraries rock.