Whitney,
Start out with Class-Yes, the Five Rules and the Scoreboard Game, and then introduce other elements as you become familiar and comfortable with them.
Remember that the average young person's effective attention span is about equivalent to their age. Think about segmenting your class into ten minute segments, each focused on a different activity. The lesson you are trying to teach can be the same, but try to vary the activity itself to regain their attention.
Remember to use verbal hooks frequently to refocus their attention- "give me an 'oh man!'"; "gimme a mathematically cool!" and so on.
When you use class-yes try not to say it the same way twice in a row. It takes more practice than you would think.
Look into the Five Point Lesson Models you can find here.
Above all, remember that you do not have to be perfect! If things do not work the way you thought they would take a step back and analyze what happened. Why did it not work? What could you change to make it even better even if it did work.