This is not a fun day out. I was affected and sad when I came back. Absolutely necessary to go and pay your respects.
I would advice you to read about it before you go. Or watch ‘First they killed my father’
At the entrance you will get audio (dutch available) and will guide you around. I warn you: it is intense!
You can get water but bring enough on a warm day because you’ll be walking for 2 hrs