Hi,
First of all which version of ZorinOS did you install: Lite or Core? Please update your profile here on the forums to reflect that to make it easier to provide better assistance.
Secondly, there's a button to edit your messages. Please use that in the future instead of opening new threads.
And finally, if you don't want to re-install the OS version entirely I think you can follow this thread to remove xfce and install gnome.
You can find the Terminal under the start menu -> System -> Xfce Terminal. Instead of looking for it manually you just type "terminal" in the start menu to run a search for that.
You can also press Ctrl + Alt + T to launch it.