Make sure you ask your leadership in your company, I'm sure they'll help you out. As a former member of Co. K I know there's a great deal of knowledge there.
Really, with regards with stuff to bring, it's not too much different then normal. The only difference is that conveniences might be a much further walk away then your used to, so it would be best to be self-sufficient to a degree. Bring period food that will not spoil, pack light so you can walk in and out in 1 or 2 trips, bring toilet paper just in case they run out, and that's really it. You want have time to enjoy the event, not tramping around everywhere looking for the food stand or stuck in traffic or whatever.
Old Northwest Volunteers
103d Co, 94th Engineer Battalion