How does it feel to go to Auschwitz death camp?

Next week my school is taking us to Poland for four days, and on one of those days we are going to auschwitz on the first day. What I want to know is how does it feel, emotionally, because i heard that you can suffer sever depression and get nightmares from it. I want to hear your experience, and how you felt, and people that you may have gone with, felt. I want to prepare myself just incase.