My son will arrive in Guangzhou Airport on 8/1. He needs to get to The China Hotel (Marriot) at No. 122 Liu Hua Lu to get a bus ticket for the following day to the Hong Kong Airport. Once he has the ticket, he needs to get to the Bai gong Hotel at No. 17 Renming Nan Road.

What bus should he take to get from the airport to The China Hotel and what is cost?
How much is a cab from The China Hotel to the Bai Gong Hotel?
Bus tickets are only sold 7 days in advance and he arrives in Guangzhou on 8/1. If it is sold out, how else can he get to the HK airport for his flight home. Thank you very much.