An actual WM is not a DE, and if you use something like i3 (sway is the Wayland version) all it does is manage your windows. A DE includes a WM; GNOME's is called ~~gdm~~ Mutter. If you install a WM yourself, that's all you get. Docks, bars, etc. might have suggested or sibling implementations for a given WM, but you'll be setting them up yourself and you can easily swap in other options, or just not have them. There's also no included software suite with things like a file manager. You're expected to pick and use whatever tools you like, which is exactly the appeal but can be intimidating if you're used to a full fledged DE.

Tiling is just a way of organizing your windows, as opposed to the more common "floating" scheme that all the major desktop UIs use. You can totally use tiling in a DE, you just need an extension for it. I know they exist for GNOME and I'm sure there's a way to do it on kde too. Even Windows has tiling modes available.

So you can probably just enable tiling on your current setup to try it out (or install GNOME on your VM --i know that PopOS! used to have a built in tiling mode, but it's been years since I tried that so ymmv). Moving to a WM instead of a DE is a very different and more involved process that's mostly for people who want a totally custom setup with no extraneous features that they don't explicitly set up. It's basically the UI side of doing an LFS or classic Arch install where you pick which system components to use by hand.