“How many languages are spoken in China? According to Ethnologue.com there are 292 living languages in China. Many others exist, but are extinct today.”
Here’s the beginning of an article I spent some time doing research for 
I am not an expert on the history of China, nor on the linguistics of each languages so I have learned a lot while working on this article.
It really reinforced my idea that the Chinese languages and their history really are fascinating!
This is a very extensive topic, so I tried to keep it simple allowing readers to quickly find and easily understand the information they are looking for.
This could be a good starting point if you are doing research for school or for your personal projects.
I found that the information available online were either very complex and difficult to understand, or the explanations very messy. So, I hope you will find this article interesting, a bit more structured and easy to navigate 