Arriving at 20.20 at Pudong airport need to make it to shanghai railway station

It is possible to take subway to reach that station, but it is suggested to take the airport shuttle bus line 5 to reach railway station directly. You need transfer if taking subway trains.

It is almost impossible to buy the same day D-train ticket to Xian on your arrival date, because there is only one train. If possible, you are highly suggested to book in advance and then collect it at the railway station on your own.