Choosing a Distro
This will be one of your biggest first challenges when it comes to Linux, choosing your first Linux Distro. Understand like dating, and unlike say religion, this may not be your last Linux Distro, and you may distro hop a few times, and maybe back and forth before deciding upon one. Or you drink the Kool-Aid and follow the faith of one distro from the start to end. Go Purest You! Depending on your devices, you may end up with more than one, Sensei.
This is not anywhere near as major as other life decisions unless you are dealing with mission critical systems, in which case, why are you hear reading this, but for all others, this is a serious, not so serious decision. Look into it, see which may install with the least effort given your hardware and then proceed. Or just say screw it and install them all, one by one, either way, you do you.
Package Manager
One of the biggest differences between most Linux Distros, especially, unrelated distros, is the package manager. This really entails its a page on its own, and we have that in, "What is a Package Manager?", which you can decide the order read that first then this, or finish this then that, either way. The package manager is a major aspect of the distro experience and depending on your experience, if you love or hate your first Linux Distro, the package manager may play some role there in your experience.
For our purposes here, a package manager is a piece of software that you will use to install, update, and all around, manage all the optional and non-optional software on your system. Most everything on a Linux system, any Linux Distro, will update all the way down to the kernel itself, so every piece of software is managed by the package manager, outside of anything you install or is installed via packages such as python's pip, node.js npm, or similar, and even support for those will vary among Linux Distros.
Release Type
This is not political and for simplicity sake only, we are grouping things into two types of Linux Distro release types, Rolling and Versioned, there is likely not many if any other forms or even hybrids. If you know of others, contributions are welcomed, otherwise.
Rolling Release
Rolling is when a Linux Distro never has a release or version, it just keeps rolling along, as software changes you update. Rolling Linux Distros have both pros and cons, they allow for a installation to exist for a vary long time providing it is maintained and updated properly, which is a good thing for servers and other long running systems. However, Rolling Linux Distros can be tricky to maintain as major updates can cause breakage that you must fix, or do the Windows thing, reinstall the operating system; this is frowned upon in Linux, fix it, don't reinstall it. Only a few Linux Distro's use rolling release models.
Versioned Release
Versioned releases are what most people are used to when it comes to software and operating systems, you are are running software version something and your operating system version and/or name. When it comes to an operating system, versioned Linux Distros have pros and cons as well. A pro is that major breakage tends not to occur with updates as you are running a specific version of said Distro for some period of time it is supported. When that time expires, or a new version comes out, you must update to that version and most times, a full re-install is recommended, and this involves downtime, backing up files, and other things, which are the cons. Most Linux Distros fall under the Versioned Release model.
Linux Distros
Ok, so lets get to it, here are some of the primary Linux Distros, grouped by Package Manager, but again, we will not be cover that topic there here, see "What is a Package Manager?". Aside from package managers one of the other biggest difference is the package formats used by each Linux Distro.
Red Hat Enterprise Linux (RHEL)
This is probably not the first distro you will start with unless you are in corporate or government, or other commercial industry. Red Hat Enterprise Linux is considered the gold standard, though like anything with Linux, this is subject to opinion. Commercially, IBM with its Red Hat Enterprise Linux product is the most commercially successful Linux Distro, along with top Linux certifications, but this is also the most expensive Linux Distro to run. You can also buy systems with RHEL pre-installed.
Red Hat Enterprise Linux uses the rpm package file format and is versioned.
Fedora
This is one of the best first and long term user Linux Distros and will feature the best Gnome and Wayland support as both are developed by IBM/Red Hat, and Fedora is the pre-cursor to RHEL product, things are developed, experimented with, and tested in Fedora before maturing to RHEL. The Fedora Project is a great first start for many and has potential to be your first last Linux Distro.
Fedora Linux uses the rpm package file format and is versioned.
SUSE
This is one of the main commercial alternatives to RHEL and is primarily used for commercial purposes, and is not as likely to be your first Linux Distro unless like RHEL you have industry exposure. SUSE product is commercially successful Linux Distro and is less expensive than RHEL but still expensive. You can find some vendors to buy systems with SUSE pre-installed.
SUSE Linux uses the rpm package file format and is versioned.
openSUSE
This is another solid first Linux Distro and is similar to Fedora in its relation to RHEL as openSUSE relates back to the commercial SUSE products. openSUSE is a great first start for many and has potential to be your first last Linux Distro.
openSUSE Linux uses the rpm package file format and is versioned.
Debian
This is one of the oldest and best Linux Distros and you cannot go wrong starting here, although, there are some more modern alternatives that are more up-to-date. Debian does not pride itself on having the latest versions of all software. It prides itself on being the most stable and tested of Linux Distributions, in theory, and this is why Debian can seem to lag other Linux Distros and take years for some updates to be in the latest version. Nonetheless, Debian is a great first start for many and has potential to be your first last Linux Distro.
Debian Linux uses the deb package file format and is versioned.
Ubuntu
Ubuntu is in short a commercially backed version of Debian, developed and supported by Canonical, which offers free and paid versions of Ubuntu. Canonical builds upon Debian and has refined various aspects for a improved end-user experience. This is the second, or arguably, first best distro for anyone new to Linux, and features a very large community and a lot of documentation and resources. Unlike Debian, Ubuntu tends to have the latest version of software available. Ubuntu is a great first start for many and has potential to be your first last Linux Distro and you can find vendors who sell systems with Ubuntu pre-installed, though some only the server and commercial versions.
Ubuntu Linux uses the deb package file format and is versioned.
Arch Linux
Arch Linux is a more advanced Linux Distribution that may not be the best first Linux Distro, but if you are up to the challenge, could be great, and being rolling, could be your first last Linux Distro.
Arch Linux uses the pacman file format and is rolling.
NixOS
NixOS is a unique Linux Distro that combines both package management and system configuration through a functional language that describes the system configuration and uses the Nix expression language for declaring packages and system options with package definitions originating from Nixpgks collections. Nix packages are built from source, so this means packages will take longer to install and you will need to configure build and other options. NixOS is a more advanced Linux Distribution that may not be the best first Linux Distro, but if you are up to the challenge, could be great.
NixOS Linux uses the Nix build language package file format and is versioned.
Gentoo Linux
This is one of the most advanced, customizable Linux Distro's out there, that is the basis at times for entire operating systems like ChromeOS that is built using Gentoo's Portage package management system. Gentoo packages, ebuilds, are bash scripts that wrap existing build systems, and most all packages are compiled from source with select binary packages available. You will spend hours building packages and the Gentoo ebuild USE flags, configurable package options, can overwhelm even the most advanced Linux users. Gentoo Linux is an extremely advanced Linux Distro that may not be the best first Linux Distro, but if you are up to the challenge, could be great, and being rolling, could be your first last Linux Distro. Gentoo is one of the best Linux Distros from learning Linux from A to Z.
Gentoo Linux uses the ebuild file format and is rolling.
This website is hosted on a Gentoo Linux server, a Linode, in Akamai Cloud, the JaxLUG has a history of being hosted on Gentoo Linux servers!
Slackware Linux
Slackware is the oldest still maintained Linux Distro where you do everything, there is no Linux that is more cumbersome to install, maintain, or otherwise, as you must handle installations including package dependencies yourself. This is not a good first Linux Distro unless you seek to learn an awful lot and do it yourself. Others are likely better suited, but there is still a vibrant community. The Slackware Linux Project is a very advanced Linux Distro that may not be the best first Linux Distro, but if you are up to the challenge is a great Linux Distro.
Slackware Linux uses tarball file formats and is versioned.