In this course I use After Effects CC on Windows 10. There are many shortcuts that I will mention.

If you are on a MAC you can replace:

CTRL or Control with Command on Mac

ALT with Option on Mac

Example CTRL+C (mentioned as Control C) will Become Command+C on Mac

Example CTRL+ALT+Home (mentioned as Control ALT Home) will become Command+OPT+Home on Mac

To get all the Shortcuts in After Effects you can follow the link:

https://helpx.adobe.com/after-effects/using/keyboard-shortcuts-reference.html

For New MAC Users: 

Note: On Mac OS, some keyboard commands used to interact with the operating system conflict with keyboard commands for interacting with After Effects. Select Use System Shortcut Keys in the General preferences to override the After Effects keyboard command in some cases in which there’s a conflict with the Mac OS keyboard command.

You will find this footnote on page 29 of the document (or Page 34 PDF) https://helpx.adobe.com/pdf/after_effects_reference.pdf

Thanks 

Happy Animating