Hi Luca,
That's great that you're working on getting your license and trying to learn as much as possible. When it comes to learning how to build a business as an agent, if I had to choose one book to read for the rest of my life, it would be The Millionaire Real Estate Agent by Gary Keller. This book is full of great information and from what I can tell, it is the book that many real estate agents use as the framework for growing their businesses.
This book spends a lot of time talking about where your priorities should be as an agent. For example, Gary Keller goes into depth about the "Three L's of the millionaire real estate agent." Here, he explains how leads, listings, and leverage should be at the top of the priority list for an agent. A successful agent should be constantly generating leads and keeping their pipeline full. After all, no leads means no sales. Listings are important for many reasons such as marketing opportunities and more lead generation. Also, leveraging other people's skills and time can help you become more efficient and maximize how much you can get done.
Gary Keller also talks extensively about which steps an agent should take while scaling their business in terms of delegating responsibilities. Even for people who are not aspiring real estate agents, this book is a great read simply for the greatness mindset it helps cultivate for the reader. The book is riddled with inspirational quotes and what Gary Keller describes as "MythUnderstandings" that stand in the way between a person and high achievement.