Gz, to Shanghai.

On September the 23rd, we will arrive at Gz, airport. We then have 1hr:40 mins to get the plane to Shanghai, Hongqiao, airport. We cannot seem to get the information required, even though I had a live chat with China Southern, and the booking company. Will our luggage be put on our flight to Shanghai automatically, or do we have to collect it ourselves? If we have to collect it, do we have to go through customs or not? Which terminal does China Southern land at, coming from London? I realise how huge Gz airport is, but does it take long to find the China Southern desk, domestic flights. Any information would be useful.

Thank you in advance,
Peter