What is Time duration taken by metro from Guangzhou south to Baiyun Airport

Hi there, can anyone advise (1) how many hours (how long duration) does the metro Line 2 & transfer to Line 3 take from GZ South to Baiyun Domestic Airport? (2) Is it easy to find the airport metro Line 2 while inside GZ South, is it in the same building? I have a Domestic flight to catch & need to know how much time to allow for travelling on the train from Zhuhai & the metro to airport. thanks. from Eddie Wong