I haven't really used Linux, but I feel it might be useful for a potential project. Is it possible, and how doable is it, to have a password locked admin account and an open user account which is heavily restricted on what they can do? As in, not even browse files. Preferrably only desktop access where they can launch the apps placed there. Which Linux would be the best for this while still being on the easier side to figure out? I do understand tech somewhat well and quite enjoy problem solving, so doesn't need to be ELI5 territory.
Yeah, came here to also say this is called Kiosk mode. You can also not have the filesystem writable and only have user files in (volatile/temporary) memory and everything set back to default once the user logs out. This is used in libraries and on computers in schools. Like a "Live-CD". And in my library the computer just logs out the user after 5 minutes of inactivity. Clears everything, sets everything back to default, opens the browser fresh with the homepage of the library.
The concept with the files in RAM ins usually called 'ramdisk'. It is a virtual filesystem on top of the write-protected one that doesn't ever change.
I think you can also prevent write access in general, but there are some caveats to that. Depends on the use-case.