Mrs. Hanna, your ticket will have numbers for the train, date, time, car and seat or berth and level. Finding the train platform and car is a simple process. When you first enter the station there will be a list of train numbers displaying the trains soon scheduled to depart. You will follow the signs for your train to the appropriate waiting room. Once the boarding is permitted you will go through a gate and follow the signs to the specified platform and once there the cars are numbered from one end of the train to the other (the number is displayed near the top of the door at one end of each car). The conductors at the car door will check your ticket to ensure you have the right one. Your seat or berth is also identified by number. If you have a berth and can't understand the character for top 上, middle 中 or bottom 下 almost anyone in the car will help you to understand which is yours. Some cars also have upper and lower levels for seats.

Thank you very much , David. Say me only, please, are the train and car numbers in china charakters or not?
I hope that not!
Hanna.

The codes of the train and car are written in Arabic numerals and letters. You can read that on the ticket.