First metro leaving Baiyun Airport

As I know, you need to take Subway Line 3 and then Line 2 to the South Station.
Subway Line 3 is available from 6:10 to 23:15. By the way, the transfer is at Jiahe Wanggang Station.
As for trains to Huaihua, they leave at 7:28, 8:22, 9:01, 14:52, 16:42, and 17:17.

Thank you, Julian! It seems from one end to another, close to 30 stations. How long is the train journey? more than an hour? before book speed train tickets online. which online site would you recommend? possible to buy ticket when arrive at South station in morning peak hours?

No worries, glad to do a help.
The train takes about 4h 30 minutes, and I was told many travel agencies provide the booking service, so does TravelChinaGuide, and you may connect them through bookingtravelchinaguide.com

Hi Julian

4 h from GZ to Huaihua, is that what you mean? Not Baiyun Airport to GZ south station, am I right? Haha! Reckon Baiyun to GZ South by Metro takes close to 2 hours?

Yes, you can get to Huaihua within 4h 30 minutes. But 2 hours is too long for the subway ride, it only takes about 70 minutes.