When opening a new project for the first time, you will see the Default Layout.
This layout provides the most common windows used and in a configuration good for smaller screens. Additional windows can be added through the Window menu in the taskbar.
The windows of the default layout are as follows:
Hierarchy Window
This window shows a text list of game objects within your scene.
This window shows the files and folders in the Assets folder of your project and is where all of your assets (materials, scripts, sounds, prefabs, etc.) can be accessed.