AutoCAD's layer system is quite complex and can be daunting to the first-time user. But you don't have to learn everything about layers at one sitting. First, just understand the basics-what layers are used for and that all objects have a layer assignment. Then, learn how layers are created and how objects are assigned to layers. Next, you'll want to know about the ways layers can be turned on and off. After that, you can explore the other layer options as needed.
In conjunction with layers, you'll want to understand how object properties work and how they interact with layers. This is an area you should have at least some familiarity with even as a beginner. Understanding properties will help you understand many of the other ways that AutoCAD can help you organize drawings.