I just discovered retool and it looks awesome.
However, I am struggling to understand how to add different pages connected to different navigation items. I have menu items and each of them should have a different page. I would have expected that once I click on a menu item, it changes the content of the page so i can start build it 
It might be a stupid quesiton, but how do i do this?
@mmaestrini , welcome,
Retool apps are single page applications, you can't add extra pages.
Each functionality gets it's own app.
You can link to other applications using button event handlers (navigate to app).
I've used the "Tabbed Container" to be able to add some extra pages/sections to separate some data fields. But I'm not sure if you want to use this if the functionality is very different or if it's using lots of other queries and functions. Maybe it might slow down overall app performance?