Hello Danilo,
First of all, welcome to the community!
There are numerous possibilities to begin and learn OutSystems. You can choose to embark on a self-guided journey, following the guided paths and pursuing certifications at your own pace. I highly recommend starting with the reactive guide path. Alternatively, you can apply to OutSystems schools, which offer two-week courses provided by OS. You can also explore training partners by conducting a simple online search. Some academies to consider include ITUp, Academia de Código, RafaOutSystems, and more.
I've also noticed that you're based in Portugal, and I'd like to share my personal experience. I began my journey in a company three years ago with zero experience and knowledge in OutSystems. The company offered an internal boot camp for new developers, which spanned three months and provided guidance before we joined customer projects. This is a common practice in many large consultancy companies here, and you might find it beneficial to explore this option as well.
Anyway, the approaches suggested previously are also a nice starting point.
Best regards and best of luck on your OutSystems journey!
Ana