Is there any depth in learning the eight-character theory? How to get started? Can you understand?

The depth of the eight characters is really unusual. Some people have studied all their lives, but they just can't get in. They have been wandering at the door. If they want to learn, they must find some genuine introductory materials, otherwise they can't even find the main entrance. I recommend a picture to you, hoping to help you, but if you really want to learn, it will be difficult at first, and even make you fidgety. As soon as you enter the door, you will find that this is really a vast and profound world, and all the contents in the picture can be downloaded online.