Are you asking how much the retracement amount is or what you're supposed to do during the two hours while you wait for the move?
Estimating the retracement amount depends on what type of strategy you employ. It can be a general 50% retracement or a calculation based on pivot points, Gann, Elliot, Fibbonacci, or standard deviation. They all have their merits but you have to choose one method and be consistent.
As for the waiting issue, well that's the drawback of only trading one security (ES). You have to wait for the good trade. Fortunately, I trade stocks so I have a lot of potential plays to choose from!