I need 2 bags for one hole and all the video's show add the bag, then about a gallon of water. So how would I do it for 2 bags? 1 and 1 or 2 and 2?

Fill the hole 1./3 full of water and then start pouring in the Fast Setting Concrete Mix. If the mix starts to dry us a you pouring then add some more water, then continue pouring the concrete until you are finished.