Super is hardly what I consider a beginner's tool!
You should try something simple at first, like this one: Freemake - Best Freeware Alternatives To Paid Video Software
1)drag/drop your Mpeg clip into the window
2)pick a base format from the bottom and
3)fine tune it with the drop down arrow to fit your needs like this:
After you picked your preset you will see the estimated resulting size in the bottom right.
In this example I squeezed a 1.46GB MPEG-2 into a ~700MB MP4 with virtually no loss of quality that's a gain of more than 50 % space and it took all but 10 minutes
Just one more word to precautions: Try not to change the original encoding around too much to get decent results like change the screen resolution but leave the frame rate alone. Set the Bitrate to auto until you get a hang of it and at least in the beginning don't delete the original before you checked the results !!!