Can anyone tell me how to get from guangzhou to shekou in shenzhen?

Generally speaking, you can take the D trains from GZ to Shenzhen Railway Station in Luohu area. After arrival you can walk to the Luohu Station to take the subway Luobao Line to Window of the World. Then transfer to Shekou Line to Shekou area. If you want to Shekou Port, you can take the Shekou Line to Shekou Port Station and then you can see the Port after you get out of the station.