So, to be able to copy / paste to / from the desktop from Nautilus or nemo (you have to install nemo but don't have to use it) :
1 - Install nemo
2 - In gnome-tweaks (install it if you don't have it), go to the extentions menu desactivate the zorin-desktop-icons
3- In a terminal : nemo-desktop
4- Try it. You should now be able to paste / copy from to the desktop.
5- If you like it, just add it to the startup applications
I respect other people work, but seriously gnome people, a desktop is not a piece of renaissance art; just let us use it.