Planning to go from hangzhou airport to shanghai modern art museum on 5th Nov.

Do you mean you want buy the train ticket at the airport? If so, you can’t do that, you need to go to the train station to buy the tickets.
Airport to Train Station: Take Shuttle Bus – East Railway Station line and get off at East Station. It takes 30 minutes and CNY20.

Take high speed train to SH Hongqiao Railway Station, and it takes about 70 minutes and CNY117 for a first class seat, CNY73 for a second one.

Hongqiao Station to the museum: Take metro line 10 and transfer to line 8 at Laoximen, get off at Xizang Rd (S) from Exit 2, and then walk northeast along the road for 10 minutes and turn right at the second crossing to Huayuangang Rd, walk southeast for about 8 minutes, you will get there.