I will go to Beijing, Guilin and Shanghai. Is this a good time to go?

If you plan to visit the rce terraces, then I think you may postpone your trip one week later. The best time to visit the rice terraces are in May, June late September and early October. If you are lucky, you might see golden rice terraces in late September.

You know, Chinese National Day Holiday is from Oct.1 to 7. There will be many tourists at the tourist attractions. So you may avoid traveling during the holiday.