hello My arrival in pudong is 8pm and next flight is 8am in Hongqiao t2 ?

Oh, you have enough time to do some night entertainment activities. But if you wanna leave the airport, you need to apply for the stay permit first.
Upon landing, you can take subway line 2 to get to People's Square Station, Exit 20. Then walk to famous Nanjing Road. You can taste many local snacks and appreciate the beautiful night scene of Huangpu River.

According to your departure time, there is no bus or subway for you to take. So you are suggested to take a taxi to arrive at Hongqiao Airport directly. :-)