All you need to do is let them know what you need so they can provide the best service possible. The final responsibility of all aspects of the train, including service and safety, lies with the Conductor, but he is not alone. Serving you to ensure both comfort and safety are the Engineer, Assistant Conductors, the Chief of On-Board Service and Service Crew, the Chef and Kitchen Staff, the Steward and Dining Car Crew and the Coach and Sleeping Attendants. Any one of them is available to answer your questions. The first thing you can expect is the luxury to enjoy something you rarely get to enjoy - time.
Train travel is unique - there's simply nothing else that can compare.
Soon you'll stretch like a cat, take a deep breath and realize your heartbeat is a little slower than before. You've settled in and time belongs to you. The second thing you can expect is spacious seating. If you are in Coach, you'll find your seat is big, comfortable and unassigned. Pick the one you want.