Gnome version: Just right click on your taskbar (or panel), and it should bring up a menu with an option "about gnome". Click that and you'll get the version and some other information.
Do you mean terminal as in a usable terminal, or a background image? For the first, you probably have a list of terminals in one of your menus on the "foot" menu. It's "GNOME terminal". For the second, you'll have to take a screen shot of a terminal window, and then use that picture as your desktop. What you'll use for the screenshot typically depends on what distro you have. Then with your desktop showing (windows minimized), right click on your present background. Select "change desktop background", and your desktop preferences will pop up, along with the stuff to select which background image you want to use. png is probably the best format to save your screenshot in, as it's what GNOME uses for it's own default pics, but you can use others as well.