You now struggling with the Unity interface ? (the one with the sidebar "Launcher")
Click the top icon in the launcher (or hit the super key) .. then start typing terminal
(into the search area) and you should see an icon for it appear below.
Or you can browse the installed applications from there too.
Once you start an application .. its icon will appear in the "Launcher" sidebar .. if you want to keep it there as a quickstart launcher, right click the icon in the launcher, and select "keep in launcher" (or similar).
BTW, you can always open a terminal with Ctrl+Alt+T
Oh, and when you get fed up with Unity .. ditch Ubuntu and install Peppermint, which is MUCH quicker as it's Ubuntu 12.04 based but uses the more familiar LXDE desktop environment .. tutorial here:http://linuxforums.org.uk/index.php?topic=10313.0