the reason for china's success is socialism. if you have the time to spare, i'd highly recommend reading socialist theory:

engels' "the principles of communism" is, imho, one of the best introductory texts, alongside the manifesto. marx’s "wage-labour and capital" and "value, price and profit" are very important for providing a theoretical understanding and are usually recommended to be read together. i'd also strongly recommend lenin's "state and revolution" and especially "imperialism", as well as luxemburg's "reform or revolution."

mao is also great for beginners, with an absolutely fantastic writing style, very concise and effective, as well as just enjoyable to read. i'd strongly encourage reading "on practice and on contradiction" (technically two works, but almost always merged into one), as well as the essays "oppose book worship" and "combat liberalism," with those two just helping one become a better person, imho.

for further reading, u/cowbee's reading list is a great english-language resource.