if you place your cursor in the bottom right hand corner you'll see the Windows 8 charms appear. Click on the wheel or settings and you'll see a panel appear with options that include shutdown.
Our tutorial section has many threads regarding Windows 8 but to get you started check out this web page:
What model Samsung do you have? I have a Samsung RV511 that does have the 2 right/left keys just below the touch pad. I'm guessing that all you would have to do is double tap the touch pad in it's respective places to perform those functions.