Hello I'v played dead rising and I want to know if you can return to a place after awhile and find new things like survivors?

You will get survivors who pop up in places you already visited. Most survivors are time related so you could go to a spot a million times but that survivor won't pop up until a certain time in the game. Others can always be there so it just depends on the survivor. Just answer Otis' calls and he will tell you were the survivors are. Some survivors depend on bosses also so just be sure to answer the calls.