Huangdi Neijing is an ancient book that records ancient life sciences. Mainly divided into two parts. The first part is the description of life structure and its operation law. Part of it is about how to diagnose and treat life problems. Strictly speaking, all the translations of Huangdi Neijing on the market are literal translations. A better version will have a little in-depth interpretation, but it is far from its meaning. Because if we want to fully understand Huangdi Neijing, we must be able to understand the Book of Changes and the operating rules of intangible parts of life, such as the meridian system, the movement law of qi and qi over time, the existence form of soul and spirit and its life function, and even the evolution law of astronomical calendar: five movements and six qi. These are not the knowledge that textbooks can learn. It belongs to the secret system in Chinese studies. However, if it is relatively better, I recommend you to have a look at The Complete Works of Huangdi Neijing (a rare edition) edited by Mr. Liu Yongsheng, which can be bought online and published by Chinese Publishing House.

As for Compendium of Materia Medica, the essence of its book is the ancient taxonomy of life, because in the tradition of Chinese studies, everything is in the yin and yang and the five elements, and the five elements are related to life and grams. Therefore, when the yin and yang of the human body are unbalanced (sick), these things can be used to regulate the yin and yang of the human body. So if you really want to understand Compendium of Materia Medica, you don't have to memorize the knowledge of meridian tropism and medicinal properties of those drugs, but you should explore and understand the mechanism behind these knowledge. This is the real core of TCM knowledge, but it is also a profound knowledge system. There can't be books on the market, but you can get in touch with this knowledge by studying the Book of Changes. This is a work of the Ming Dynasty. It is recommended to read the original text and recommend the translated version:

Compendium of Materia Medica (color map analytical edition) (a set of 4 volumes) Tianjin Science and Technology Press.