In Civilization VI, each civilization has two abilities. One is based on what the nation has done throughout history and the other is tailored to what happened during the ruler's reign. China's special ability is called Dynastic Cycles, which provides a larger boost from Eurekas and inspirations compared to other civilizations. Qin is a ruler who gets things done. His builders receive an additional use and he can use Builders to boost construction on ancient and classical Wonders.
The Great Wall has returned in Civilization VI, but now it is a unique tile improvement for the Chinese. At the start of the game it will provide defense and gold and as you advance through time it will give you bonus Culture and Tourism. Keep in mind that because it's a tile improvement you'll have to keep dedicating Builders to the task of expanding it, just like in history.
Like Egypt, China is a Wonder focused civilization in the early game, but unlike Egypt, China can be much more defensive and insular.
The Great Wall will be a formidable barrier to protect you in the early game.