Hello @Carlos Martinez.
welcome to this moderated Azure community forum.
The easiest way to train yourself for the AZ-900 exam is to start with the three self-paces MS Learn paths collection seen at the exam page.
Once you are confident, you could try the free practice exam. There is even a demo to exam experience.
Finally, check out the Microsoft Azure Virtual Training Day: Fundamentals. Join Microsoft at Azure Fundamentals to develop an understanding of foundational cloud concepts and expand your knowledge of cloud models and service types. Space is limited, so reserve your spot now!
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