Resources for making non digital natives understand digital Interfaces

I often struggle to explain to my father how to use the computer, or when i try to explain to my grandmother how to accomplish certain things on her smartphone, because they don't seem to understand the basic principles of digital interfaces.

For example, i believe my father doesn't understand the concept of downloading a file from the internet through the browser, saving it in a certain location and retrieving it from the location through the file explorer.

He also doesn't seem to understand that smartphone apps follow logical rules in the menu design and that you can just move back with the arrow, instead of closing the whole app and starting in the beginning.

Of course i'm speaking from a very privileged point, because i grew up with such concepts and had a lot of (free)time to adapt to the technology, but i think my father and my grandma could profit heavily from understanding these concepts and then applying their knowledge when trying to achieve something new.

So my question is: Are there resources or techniques to teach non digital natives how to interact with digital interfaces on a broader scale, rather than teaching them how to do one specific thing?