Where to take train bullet from shenzhen to shanghai, since i'm coming from lowu? Many thanks

Pass the border at Lowu to get to Luohu. Then you need to Metro line 1 and transfer to line 4 at Convention & Exhibition Center, and then get off at North Railway Station. Then you can take a bullet train to Shanghai, which takes about 12 hours and CNY909 for a first class seat, CNY568 for a second one.