Who was the first person to discover China?

The question is misleading. China has existed as a continuous civilization for thousands of years, and therefore was not "discovered" by any one person. People have been living in the region now known as China since the Neolithic period, and the first major civilization in the region, the Xia Dynasty, emerged in the 21st century BC. Throughout history, various explorers, merchants, and travelers from different parts of the world have visited China, but the concept of "discovering" China as a new land does not apply in this context.