I am going from Nanning to Shanghai by bus or train. how can i find the schedule of bus or train?

Well, you are suggested to take a direct normal speed train from Main Railway Station because of the long-distance. The schedules are 08:00, 08:15, 13:25 and 22:15. It takes around one day and four hours.
Or you can take the bullet train from East Railway Station. It departs at 09:05. The duration is about 12 hours.
You can get the schedule by searching on this website.

If you wanna take the long-distance bus, you can take it from Jinqiao Bus Station. The deparure time is 11:50.

Victoria thanks so much, ur information help me a lot

Hi Victory,
Do you know how much taxi cost from Vietnam border to NN train station?
Thanks in advance

Well, maybe it's not easy for you to find a taxi that can take you to the destination because of the long-distance. So you are suggested to hire a private car directly. The fare is CNY 900 to 1,100 for the single trip.