The word you're looking for is Desktop Environment (DE). KDE Plasma is one such DE. Distro is the underlying system.
- i3 has been around forever and has lots of guides on how to customize it. Only downside is it's X11-only, so as everyone moves to Wayland, X11 support will decrease.
- Sway is i3+Wayland, though it's newer, so I dunno how much customization content is out there or whether the i3 tutorials are forward compatible.
- Hyprland is another popular choice, and it is Wayland-based. Only downside is the project lead is a toxic asshole, despite being a gifted dev.
- Cosmic is an upcoming DE, so if you're in no hurry, keep an eye on that one.
To install any of them, search for the project and see if they have an installation guide for your distro. If not look up "how to install \ in Fedora."