If that doesn't make sense, go look one up. Yeah, they are all conflicting. And that's totally fine, everyone has their own opinion and all, and this is mine, but some of them have bias towards some environments. That's obviously not saying that I don't have any bias, but do take this whole thing with a grain of salt.
Okay, let's break this down. When you use any Linux system with a desktop, you are using a Desktop Environment. This essentially is the thing that gives you something to look at, other than just a terminal. These environments also give you some programs to use, ranging from things like web browsers to things like app browsers.
Do note that you can freely install programs from other Desktop environments, they just might have some problems.
Actually, yes. Mixing Desktop Environments can be very risky, for one. Sometimes they might break your entire system if you do it wrong. Sometimes they might be totally fine. There are actual ways to make it work, and I will list it later, but for now we're focusing on the list.
If you pick a distro, or a premade Linux setup, chances are it comes with it's own DE
Obviously I can't exactly list a pros and cons, as most of these have the exact same functionality with some configuration, but I can list features and any problems I have had with the one's I've used. Trust me when I say I have had problems with all of them.
My go-to DE. It does have it's own fair share of problems, but I enjoy it enough for it to be my main DE.
If I'm not using XFCE, I'm using KDE Plasma.
This is only for Arch Linux
I don't particularly love using Ubuntu, so I don't know how to do it on Ubuntu, obviously.
Simply use a Virtual Machine of choice (Oracle VM VirtualBox, QEMU, etc.) to install a Distro that uses the DE you would like to test. This lets you configure and use your DE without affecting your personal computer.
Install your DE of choice through Pacman. Then create a new user specifically for said DE. Log out from your current user, and on the login screen, simply switch accounts and there should be a space to select your DE of choice.