Librem 14 updated and working after two years of trying

What is a good way to learn all of this language I do nit innerstand? Grub,Boot configuration,
The general approach is:

  • Enable legacy boot mode
  • Ensure current OS boots in legacy mode
  • Install Qubes
  • Manually add boot stanzas to /etc/grub.d/40_custom
  • Update
    I assume these commands are performed in the recovery shell?