I literally was thinking of starting a channel just so I could speak about what you mentioned.
I see people moving on to Linux from Windows (which, by the way, I think is a blessing!) but with little to no clue on how Linux works. It certainly doesn't help that the Linux ecosystem is so diverse, because even choosing a distro can be daunting. So having a clear cut path could help tons of people do the transition.
Would that add value to you? Let's say, multiple videos explaining the filesystem, useful commands and best practices, useful shortcuts and how to customise your desktop to your flow, etc
Also, I find the content by @TheLinuxExperiment very informative and a good way to keep up to date with things. It also explains the difference between distros, ways to install apps etc..
Uff, 6h is a stretch. I often space out in videos longer than 10mins ๐
Reading wise, maybe I can recommend you linuxjourney.com. It won't answer the backups question, but it's a great way to nail the fundamentals! I can't recommend it enough, it's like a free course :)
As for the backups bit, Pop!_OS offers an OS refresh feature where your files are kept instact, afaik. So depending on your chosen distro, you might not even have that problem! Otherwise, DejaDup does a good job backing up personal files, but not system settings, I believe.