You don't need an article to know the layout in Nebo, only maybe to be familiar with the name of our User Interface (UI) elements.
The most common UI elements in Nebo are:
The side panel
The pane on the left, where you'll find the Notebooks, Settings, and Help sections.
The main view
The view on the right, which stretches over two third of your screen. It's where you'll see and be able to manage your notebook pages.
The add object menu
The menu to add elements other than writing.