The Coach Level represents your performance as a manager during your entire career. By winning tournaments and getting achievement you will accumulate experience points (XP). Once one of your players has established an age record in a category, your following players need to beat that record to bring you more experience. This XP will increase your Coach Level.
The Coach Level is an essential parameter when you want to upgrade infrastructures and when you search for new talents to manage. First, it allows you to improve your Youth Camp and thus attract better talents. Furthermore, for a given level of Youth Camp, the higher your level, the higher the probability of finding and convincing the best players.