The Coast Starlight is a beautiful trip, particularly from LA to San Francisco. As with most Amtrak trains, Coach is first come-first served. You get on the train and start looking for an empty seat. If you have trouble finding one, the car attendants/conductor can help. When the conductor comes through and collects your ticket, he/she will put a seat tag above your seat. That tag says this seat is occupied until and says your ending stop in a sometimes obscure conductor code. As the train approaches the next station, the conductor will come through and take the seat tags for everyone getting off at that stop, wake them up if needed, and announce the stop. If you don t like your current seat, watch to see who had their tags removed. When they get up to leave, take YOUR tag and move to the new seat. Coast Starlight also has a lounge car you can hang out at. Leave your seat tag if you leave your seat. If you have lots of luggage, you can check it at the station and pick it up when you get to your final stop. However, not all stops on all trains can handle checked luggage. Most people just carry their luggage on the train. There s more room overhead than on planes, plus many cars have overflow areas at one end. The Coast Starlight has both a snack car (Cafe) and a dining car. Both are expensive, so take your own snacks. The Coast Starlight is nicknamed the Starlate, so keep that in mind. Most cars have plugs for electronics. Your trip is overnight. Take a pillow (the ones Amtrak provides are teeney). Take a small toiletries bag with a washcloth, soap, tooth stuff, etc. In the morning, wash your face, brush your teeth, clean up pits and parts , and you ll feel much better.
I took it many years ago and don t remember. Call Amtrak and ask the same questions.