I cannot recommend highly enough an amazing book “The Hummingbird and the Hawk.”
I had a double major in college, Spanish and Archaeology. It did not take long to find out there is no way to pay a mortgage (or most any other bill) pursuing archaeology. I did get to participate in some excavations in Central America.
That said, there are amazing books that inform and entertain everyone. The Hummingbird and the Hawk details Aztec history from long before Cortez, and then the arrival of Cortez. There was a General, Tlacael, who had the ear of both Montezuma I, and Montezuma II. Cortez arrived when Montezuma II was in charge.
Another fantastic book is The Discovery and Conquest of Mexico, 1517-1521 by Bernal Díaz del Castillo. Castillo fought with Cortez for years. At the end of his life, he wanted to leave something. He was mostly blind, and dictated this amazing account from someone who was there.