how did the inmates greet the new arrivals, such as Elie and his father?h

Well it wasn't a Welcome Wagon. When they first arrive, the stench of burning flesh is in the air. Really people are too busy bring to stay alive to give Eli and his father a tour of the facilities. One man at least warns Eli to say the right things regarding age and usefulness. The Nazis wanted strong workers, not Rabies, intellectuals or children.

The prisoners who have been at Auschwitz for awhile are brutal and cruel to the new arrivals, and one of them tells them about the crematory. Some of the young men talk about revolting but are silenced by their elders.

At the barracks, veteran prisoners began to beat the new arrivals and told them to get undressed. The new prisoners threw their clothes into a huge pile.