I made a quick video for ya.
For icons on the desktop as I show just make sure its in folder view. Then you can move, sort, and lock them in place same as on windows or mac with a right click on empty desktop.
Now I hope someone can chime in with what setting you need to change so that if you have a full screen window it has window decorations when the widget/top panel is removed. As have forgotten haha.
*sorry if youtube is a bit slow with the quality-