Big like on Hansel's comments and nice to see you, Hansel
I also noticed
@wizardfromoz slipped out without any comment. He is one that has a lot of knowledge.
Haha, if I start telling Tom about the 80 Linux I run, I'll only confuse him further
Best for Tom is to have a small supply of USB sticks for him to download and try some, but importantly to identify what he wants to have in an Operating System (OS).
DistroWatch is a good spot to see what Linux are available - its page hit ranking lists many (top 100 and more) -
https://distrowatch.com/dwres.php?resource=popularity
... if he tries any of those top 10 he can't really go wrong.
For understanding of Desktop Environments (DEs) -
https://renewablepcs.wordpress.com/about-linux/kde-gnome-or-xfce/
Tom, this is a bit like the differences between Windows 98, XP, Windows 7, 8, and 10 with their "look and feel".
So LInux has GNOME, MATE (pron. "mar-tay"), Cinnamon, KDE and so on. MATE is likely the closest look to Windows, if that is what you want, so a LInux Mint MATE or an Ubuntu MATE might suit.
On Timeshift, it is like Windows Restore, but way better, and I have a Tute on it here
https://www.linux.org/threads/timeshift-similar-solutions-safeguard-recover-your-linux.15241/
... but that is best read and used only after you have made a full install of a Linux to your hard drive (if you choose to do so).
Cheers
Wizard