Personally I use Arch Linux. It does have a reputation of being the OS of choice for those insufferable people you find on Reddit showing you their dwm customizations (he says, kicking his desktop screencaps under the carpet).
I find that it has INCREDIBLE documentation on almost every facet, and if you've spent any time working on Linux, you'll probably know exactly what I'm talking about, the Arch Linux wiki is probably the single best resource for Linux information, of any sort, even if you don't use Arch, but it is of course tailored for that.
I find its minimal install environment to encourage directly understanding the system. It can also be incredibly tight and fast, with nothing you don't want on there. The package ecosystem is one of the most efficient and easy to use ones I've known as well, with pacman being a really nice tool for package management, with the only thing that may annoy you (it very rarely does to me, but I've learned to deal with it), being the AUR.
If you're currently debating between Debian derivatives, my personal suggestion is to just use Debian. The differences are so absolutely minor, and I could skin even Arch Linux to look and operate like any of them, since it's all Linux at the core. Debian does have some minor driver woes, as it only includes completely free and open source drivers, whereas Arch will include some proprietary firmwares and drivers within it, which can be helpful.
As for window managers, I would strongly recommend staying away from Wayland, for various reasons. I've found it to be chunkier than X, and when it comes to running X programs through XWayland, they are woefully inefficient and will just burn system resources. My wm of choice is Window Maker, which I think is one of the most easily and intricately configurable window managers I've ever seen, and it's an absolute pleasure to use. The only minor bother is that there is a rather poultry system for inserting .desktop links into the application menu, but this is easy enough to fix since you can /really/ configure that menu, and almost any other part of the system. It's also really lightweight, a fully loaded wmaker install running on 4 heads only takes around 4MB of system memory to run.
Regardless, the great thing about Linux is that you can dump your window manager and use a different one at a moment's notice, and just toy around with them. I still do that, and regularly try out different things and experiment. Good luck!