How to go Nepal by train from Nanjing?

Hi, I'm afraid no direct train can take you to Nepal. You can take a train to Lhasa first. Upon arrival there, you can go to the local bus station to take a long-distance bus to reach Zhangmu, where you can take a bus to reach your destination. The whole journey takes about more than two days.
For the journey by train is too time-consuming, I suggest you take a flight for convenience.
Luggage can be taken onto the train and the bus. But if it exceeds the luggage limitation on the transport, you need pay extra.

Thank you very much for your response. But are there the buses from Lhasa and Zhangmu to the boarder of Nepal available frequently or have to wait for long time? how long time will it take on bus from Lhasa to Nepal? what about the hotels in Lhasa and Zhangmu? I am a Nepalese, Do I need visa for Tibet going from Nanjing or not?