I think you can read this book first, and then see if their test results are normal or just want you to join their fitness program. You can tell them how you want to practice and what your goal is after you know it. This is very important.
In fact, the coach also arranges training according to your physical fitness test. Coaches still have some functions, such as: what posture to use when running, what breathing to use, how long to run a sprint, how long to ride a bike every day, how many dumbbells to lift, what dumbbells to choose when training, and so on. . .
The key is this physical fitness test. This test determines what kind of fitness program you want to participate in. So I suggest that you first know what kind of physical characteristics you are and what kind of exercise you are suitable for (such as middle-distance running, group running, or high-intensity sitting-up waiting)
Only in this way can we have a goal, find a fitness method that suits us, and communicate with the coach better. After all, fitness is based on oneself.
Good luck!