One important thing you need to know about distros: they’re all the same under the hood.
This is true for the traditional model in which the package manager is the main differentiator between distros. Therefore Arch, Debian, Fedora, openSUSE etc and their derivatives (which make up about 90% of the distros found on DistroWatch) are indeed mostly the same.
But the likes of Gentoo and NixOS etc don’t quite fit the bill. Granted, a new user should only very rarely (if ever) start their Linux journeys on any of these advanced distros.