Checking the operating system information under macOS
Press the Apple logo in the top left corner of the menu bar and open "About this mac"..
Afterwards, the following window should open:
Checking the Office Version
Open any Office application, such as PPT or Excel.
Go above the menu bar and press PowerPoint --> "About PowerPoint".
The following window should open:
empower Client Version
You can get this information from the empower.app. To do this, go to the Finder --> Applications via the menu bar and then right-click on empower.app --> Get info.