

Most probably graphics / nividia issue. But not a general issue, related to the configuration or hardware or something.
For most such cases when you can’t figure out anything, it’s generally a good idea to ask in your distro’s support forum. There are people who can usually help you debug a few things. It doesn’t always solve your problem, but you can get some possible pointers.
I set up Ubuntu for my somewhat non-technical brother (not as non technical as you mentioned, but not someone who will ever open CLI), and they used it happily until their laptop got too old and they had to change (5-7 years, even upgraded to next LTS once)
So, I will vote for something stable and mainstream like that. Set up steam on that, and they should be good to go.