Xiqiao - Fangcun Bus Station - Guangzhou Baiyun Airport

Hello there again.

I would like to ask if there is some direct bus which goes from Xiqiao to Fangcun. And then, I have to go from Fangcun Bus Station to Baiyun Airport. There are shuttle buses, bus please can you tell me what number should I take and what time/intervals do they come and go?

Should I buy the tickets in advance or is it enough to buy them the day I arrive?

Thank you very much for help.