I would like to know how to change my keyboard from an English layout to a Portuguese (Brazil) layout.
To change the layout, go to
System Settings ->
Then, click the
+ sign at the bottom left part of the window, choose
Portuguese in the language section and choose whatever Portuguese keyboard layout that works best for you.
If you like to have some visual cues, I made a video recently on how to do this, it's in Dutch, but if you follow the video, it's pretty clear on how to do it. YouTube video link