Hello!
I installed latest Zorin.
When I try to change the layout, the bottom right one doesn't work. The bottom app launcher doesn't appear.
Could something be missing?
It's Gnome layout. You need to click upper left corner before it appears.
This one:
is the Vanilla Gnome Layout. The Dock what You see isn't on the Desktop, it is only in the Overview (pressing Super Key). If You want with this Layout a Dock on the Desktop, You have to install the Gnome Extension Dash To Dock.
If your looking for more layouts install extension manager open it at top browse type in arc menu once installed hit the gear next to it at top tab hit menu then the menu layout lots in there...have fun