5 guides
About one week: Beijing, Xi'an, and Shanghai. About ten days: add the Yangtze, or add Guilin. Two weeks: Guilin and Zhangjiajie. Three weeks: Yunnan, then Guilin and Shanghai. The email quote is the price for your dates.
If pandas are why you booked China, go to Chengdu. On a first trip already built around Beijing, Xi'an, Shanghai, Guangzhou, or a Yangtze cruise, you do not need another flight.
The wish list writes itself: pandas, the Great Wall, the Terracotta Army, a Yangtze cruise, Shanghai Disneyland. Give each one its own day instead of asking one morning to hold three.
How to reach your Yangtze ship on night one: Chaotianmen piers in Chongqing, Maoping shuttles in Yichang, and the notices that can move your dock.
A first-timer's guide to the Yangtze Three Gorges cruise: how to choose a ship, which direction and route to sail, the cabin types, and what the shore excursions include.