In "By the Waters of Babylon," under the leadership of John, what do you think the Hill People will do with their society?

The best place to look for evidence in regards to what John's plans are for his people is the final paragraphs of the story. John has returned from New York City, and he has returned with knowledge of what the former gods really are. John discovered that the Place of the Gods was actually inhabited by normal men and women. Those men and women wound up destroying themselves in some kind of nuclear event. John is amazed by everything he sees, and he realizes the people had amazing knowledge and technology. Unfortunately, they were unable to control it all, and ended up destroying themselves.  
At the end of the story, John vows to begin reintroducing that lost knowledge to his own people. He has to wait until he is the head priest, but his plan is to help bring in a rebirth of learning. It's very Renaissance in concept. 

Nevertheless, we make a beginning. It is not for the metal alone we go to the Dead Places now — there are the books and the writings. They are hard to learn. And the magic tools are broken—but we can look at them and wonder. At least, we make a beginning. And, when I am chief priest we shall go beyond the great river. We shall go to the Place of the Gods — the place newyork — not one man but a company. . . They were men who were here before us. We must build again.