As mentioned, this tutorial uses a generalized, theoretical workflow to facilitate your discovery of the interface. The workflow is only a vehicle for learning and is not meant to be credible from an engineering or design point of view.
This workflow begins with a typical first task: setting the active project.
If Autodesk Inventor is in a zero-doc state (no files are open), you can access the command on the Get Started tab:
You can also access the project editor from the application menu.