Where to buy speed train from Guangzhou to Guilin? Which Guilin station the train will stop?

You can take the high-speed train from South Railway Station and arrive at Guilin North or West Railway Station. You can purchase the train tickts at the railway station. Or you can book them in advance. ChinaTravelGuide has this service. If interested, their contact information is bookingtravelchinaguide.com.
Besides, the train schedules are from 07:23 to 20:30. The duration is nearly 3 hours. The ticket fare of second class seat is CNY137.5 and first class seat is CNY165.
Hope helpful!

Yes. I did the booking. It is easy. Thanks a lot.