Your new project opens in the Unity Editor, as shown here in its default layout:

The Unity Editor consists of a number of non-overlapping windows, or panels, that may be subdivided into panes. Here's a brief explanation of each of the panels shown in the preceding default layout image:

• The graphical Scene panel in the upper-middle is where you can visually compose the 3D space of the current scene, including the placement of objects.
• Occupying the same panel, on a hidden tab, is the Game view, which shows the actual game camera view. When in Play Mode, your game runs in this panel.
• A third tab takes you to the Unity Asset store where you can find a plethora of free and purchased content from the Unity community, including scripts, artwork, and editor extensions.
• In the upper-left is the Hierarchy panel, which provides a tree-view of all the objects in the current scene.
• At the bottom is the Project panel. It contains all the reusable resources for the project, including ones imported, as well as those you'll create along the way.
• Occupying the same panel, on a hidden tab, is the Console panel, which shows messages from Unity, including warnings and errors from code scripts.
• On the right is the Inspector panel, which contains the properties of the object currently selected (objects are selected by clicking on them, whether in the Scene, Hierarchy, or Project panel). The Inspector has separate panes for each component of the object.
• Along the top is the Main Menu bar (on a macOS this will be on the top of your screen, not on top of the Unity window), and a Toolbar area with various controls that we'll use later on, including the Play (triangle icon) button that starts Play Mode.

In the preceding screenshot, the Main Camera is presently selected in the Scene panel, and it's Edit Mode is for the position transform, as indicated by the arrows icon in the Toolbar (shown in the following image), and by the axes gizmo centered on the camera in the Scene panel. Also, because the Main Camera is selected, a convenient Camera Preview window is inset in the Scene panel:

If any of these panels or tabs are not visible in your Unity Editor, use the Window dropdown from the Main Menu to find all the panel windows available to you. The editor interface is very configurable. Each panel can be rearranged, resized, and tabbed, for example, by grabbing one of the panel tabs and dragging it. Go ahead and try it! To the top-right is a layout selector that lets you choose between various default layouts or save your own preferences.