Which left you as a novice Linux user with a desktop environment that is very young and under heavy development and an atomic distro that you need the terminal to maintain.
Frankly, I am not sure your nephew did you a favor there.
Kinoite and Silverblue come with KDE Plasma and Gnome, respectively. Both are solid desktops, though Gnome deviates more from the classic Windows desktop paradigm. It gets the job done, if you are willing to unlearn your Windows training. If not, you will likely hate it or use a bunch of extensions to make it more Windows-like, which IMHO defeats its purpose.
You can install Flatpaks on non-atomic distros, too. The reason I talked about Kinoite in your other thread is because there is a non-destructive way (rebasing) to switch between atomic distros, while switching to Fedora KDE or Workstation would require a reinstall.
I am on Fedora KDE (not Kinoite) and I have 46 Flatpaks installed.
Easy on KDE Plasma, not sure about Gnome.
Easy on KDE Plasma, requires an extension on Gnome. Frankly, after using Gnome for a few years, I see their point. I rarely ever stare at a desktop with icons, I work with applications, which cover the icons on the desktop and require additional actions to get to them. But I like that I can put things on the desktop in KDE Plasma, though I rarely do it.
Gnome requires an extension to get a dock, in KDE Plasma you can configure the bottom panel to behave like a dock.
I actually have mine configured as a mix of a dock and a taskbar. Because I have a large monitor, my bottom panel is centered and half the width of my screen (so 25% empty space, 50% panel, 25% empty space). The panel itself looks more like a taskbar, with the launcher icon on the left (think “start menu”), then a bunch of pinned applications, then some empty space for starting additional, non-pinned applications, then the tray icons (for which Gnome requires an extension, you might notice a pattern), then the current time and date, and finally a weather widget. And if the space for application icons isn’t enough, the panel will grow to the left and right as needed (up to around 75% the width of my monitor).
Installing, especially with the new Anaconda installer in Fedora KDE, is relatively straightforward. And it is IMO a good learning experience. Just make sure you backup your data somewhere safe.
Edit: The new Anaconda installer isn’t exclusive to Fedora KDE. In fact, it was used in the installer for Workstation a few releases before it arrived in Fedora KDE.