For some time, Unity has been issuing exams that cover a range of different skills for people who are either graduates, self-taught, or are classed as veterans in their field.
If we check the prerequisites on Unity's website (https://certification.unity.com/products/certified-programmer), they tell us that this exam isn't for absolute beginners and you need at least 2 years of experience working with Unity and computer programming, including C#. This book will take you through the process of becoming as familiar as possible with Unity and its services, to the point where it might feel like a beginners course; however, I expect you to understand the fundamentals of C# programming, such as what an if statement is, what a function does, and what a class represents. If you don't, I would recommend reading Harrison Ferrone'sLearning C# by Developing Games with Unity...