1

Bus seems to be a good choice, for there is no direct train or flight from Guangzhou to Yangshuo, you need to make a transfer in Guilin. The bus from Guangzhou to Guilin don't stop at Yangshuo bus station, but do have a stop-off station nearby. The ride takes about 6 hours.

2

Buses you can usually get on the day but trains all over china book out easily and quickly

3

The train will be cheaper than the bus, at least if you go hard-seat, but you'll only end up in Guilin and have to transfer from there. You'll likely to be able to buy bus tickets on the same day you want to travel, even during National Week. The bus you want is the one that goes to Guilin: it passes through Yangshuo, and will drop you off on the side of the road near the center of town. The trip from Guangzhou to Yangshuo only takes about 6 hours: any "over-night" buses will actually end up dropping you off in the middle of the night. I'm not sure if either the McDonald's or KFC in Yangshuo is open 24 hours, but if they are they might be worth heading to if you arrive at a silly hour.

4

Thanks so much everyone. Really nervous about traveling in China as I don't speak the language.