Translation under review. The illustrations are still in Portuguese.
You stopped in the middle of this chapter.
You probably already have the door. If you have a bank account, chances are its app already has an investments section. A lot of people use the app every day to send Pix (Brazil's instant payment system) and pay bills, and have never opened that part.
This book doesn't tell you what to do with your money. We don't know your life: how much you make, how much you owe, what you need. This book is educational. It's not investment advice.
The first step is a question. Call your bank, or find a licensed professional, and ask them to calmly explain how the investments part of your account works. Keep asking until you understand. There's no such thing as a dumb question.