Is there a way to reach the national side, from the international? I arrive at the international airport, and I must take connection to a national flight. What steps should I follow? What terminals should I reach?

Great airport with great transportation. The plane train is the easiest and best way between terminals. Just walk to the middle of the terminal you are in, take the escalator down to the plane train and get off at the terminal that your plane is leaving from. Super easy there.

There is a shuttle that will take you over to the Domestic side of the airport.

It is a big airport, not to hard to get true by using the signs

You can walk from the international terminal to the others. Follow the signs overhead.