Hi, Ms Chen. Yes, you can get a flight to Beijing. There are many flight a day from Shanghai to Beijing, and a dozen of them depart at and after 7pm. Qantas is in Terminal 2. You can get the ticket to Beijing in the same terminal. The price is changeable and different every day. Usually, the night fight is cheaper. For question 2, Yes! you need to check-in again. Generally, to make a transfer from international to domestic flight, it will totally costs no more than one hour.