Assigning global keyboard shotcuts for cross-application behaviour?
macOS should get you up to speed a lot quicker.

See macOS Sierra: Create keyboard shortcuts for apps for creating custom keyboard short cuts:


  You can create keyboard shortcuts only for existing menu commands. You can’t create keyboard shortcuts for general purpose tasks, such as opening an app.
  
  
  Choose Apple menu > System Preferences, click Keyboard, then click Shortcuts.
  Select App Shortcuts on the left, click the Add button , click the Application pop-up menu, then choose a specific app or All Applications.
  If you want to set a shortcut for a menu command that appears in many apps, choose All Applications.
  In the Menu Title field, type the menu command for which you want to create a shortcut, exactly as the command appears in the app, including the > character (type ->), ellipses (type three periods without spaces or press Option-;), or other punctuation.
  Click in the Keyboard Shortcut field, press the key combination that you want to use as the keyboard shortcut, then click Add.