DO we qualify for transit visa and where do we ask for the transit? Would it be in Guangzou?

We fly from Siem Reap Cambodia to Guangzou arriving at 2315 we planned on staying in the hotel at the airport(PULLMAN HOTEL).. we then have a flight to Shanghai in the am leaving at 0900 arriving in SHANGHAI at 1120....then we have a flight to Detroit leaving Shanghai at 1620. We won't even be in China for 24 hours but are making 2 stops .