Here are some of the things that I would show new users:
Search is your friend. Show them how it works in the Finder and System Preferences.
Use System Preferences to customize the interface.
Demonstrate the Help menu and how it will highlight those always hidden menu items.
If they are using web apps, Chrome and Firefox are the same.
Where do downloads go?
If they use keyboard shortcuts, show that they are displayed in app menus and how they can be customized in System Preferences. The App switcher is the same as in Windows except it's Command-Tab.
What is the Finder and how do you use it.
Where to store files (not the desktop!).
Look to the upper right hand corner of the screen to tell what app you are currently in.
Clicking the red dot does not always quit an app.
How to install an app (if allowed).
How to backup or use cloud storage.
Troubleshooting simple things that are network dependent like printing or website connections.
Basic security procedures like how to lock the screen.
