I don't think it's generally available online public information, but remembering from my son's entry, we were told that USMA will pay for the initial trip to report and after graduation, the trip to his first duty station (two trips that are travelling on orders). The package that came after appointment with all of the information on vaccinations, law enforcement reports, packing list, etc. said that he had two choices: he could book a ticket through USMA's travel agent, Wagonlit Carlson, or pay himself and turn in receipts. Coming from the west coast, he was offered the option to fly in the day before and be put up at a Newark Airport hotel, sharing a room with another new cadet; cadets travelling alone this way were put on a bus up to post early the next morning. I don't think the package itself had any details on turning in receipts for flight and hotel, but he was given the paperwork at some point during those first couple of days, and did not have receipts with him, so he missed that window. I suspect that he could have also gone to the treasurer's office later, but it was a little too far out of daily routine and standard operating procedure for him to handle until much later in the year.
Incidentally, son said afterward that, in retrospect, he would have preferred saying his goodbyes at home and going by himself, to meet classmates a little ahead of time and get his "game face" on. Also, a classmate on this forum reserved a room at Turner's, a restaurant not too far away, for a buffet dinner the night before for any forum members and families who wanted to come -- something to think about?