

For those interested, ignoring the contradictory presentation of the riddle (as the knights themselves would not say the riddle since one always lies and one always tells the truth), the solution is simple. Ask the knights what the other knight would answer when asked what door is correct, and they will both say which path not to go to. Thus you pick the path that neither Knight says!
Logic:
Liar: Will say the wrong option, as they're being asked which door the truth telling knight would say (and they will lie about what the truth-teller would say)
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Truth-teller: Will say the wrong option, as they're being asked which door the liar would say (and they'll tell the truth about that)
NOTE: This can be expanded to a case with n doors by asking the knights to provide all the options that the other knight could say, and each will provide n-1 options, so you’d pick the one option that neither knight says. It is possible the liar may not list all options, but the truth-teller would, so the problem could still be worked out regardless (and you’d know which knight is the liar in that case).



Honestly, my recommendation for new users who are into gaming is Bazzite. Just install everything through the software store and it just works. Well, everything that’s available as a flatpak at least. Steam comes preinstalled, as do all the drivers (among some other various gaming-oriented things like kernel optimizations and Lutris), so it’s basically just install and done. The software store, Bazaar, will find basically anything a normal user needs. The nice thing about atonic distros is that you generally don’t need to do anything through the command line,as installs are perfectly consistent across all computers (so no random things breaking in the background without someone else noticing and either filing a bug report for you in the beta, or fixing the issue outright). After over a decade of Linux use, I’ve never found an easier distro. I honestly have switched to it as my main distro because I love Fedora, and the atomic features are nice (and Bazzite is just a little nicer for my use case than Kinoite).
When I set someone up with Bazzite, I just tell them to install everything through the software store, and I rarely get questions other than “how do I install this software that isn’t available on Linux”, which I usually meet with a recommendation for an alternative, or if it’s really critical, I’ll have them install through Bottles or something. I always mention the “no Adobe or Autodesk” caveot before they install, so I never really get questions about that except for “well, what would you recommend I use instead?”
As to answer your questions directly: