If you mean use the desktop, then the question is nonsensical.

If you want to go below the desktop then that's much harder, than learning an other desktop...
Harder than learning what's under the covers in windows, or any other OS for that matter?

Much of a muchness. Some things will pop up in google, or a book or a course straight off, others you'll have to dig for.

If you don't want to, that's what the desktop is for...