Hi I'm from Shanghai and want to go to guangzhou how much the bus fare? duration?

There are only two direct long-distance buses that respectively from General Bus Station and South Bus Station. The duration is 13-15 hours.
General Bus Station: 14:30 CNY 380/person
South Bus Station: 15:15 CNY 380/person
The bus website doesn't have English version. If you have Chinese friends, you can ask help for them. If not, just get to the bus station early and purchase the ticket when you arriving there.