Of course possible, Ms Nhung. To be notable is that the train from Guangzhou to Kunming takes over 25 hours. If that is not a problem, you can get to Guangzhou Railway Station to buy ticket in advance. Guangzhou East Railway Station also has one train. Bus to Lijiang can be found in Nanyao Bus Station of Kunming. It takes 8 hours. You can make a stopover in Dali by bus: 4-4.5 hour from Kunming to Dali (Xiguan), 3 hours from Xiaguan to Lijiang.