Press Command+i on the keyboard and verify its size. Open your Applications folder and select the 'Install macOS Catalina app. Once the installer launches, press the Command+Q keys on the keyboard to exit.

You may be brought to a Software Update window, click Upgrade Now to begin downloading the update. Navigate to the macOS Catalina application page and click the Get button.

These are instructions on how to make a bootable USB install key for macOS Catalina.Ĭonnect a 16GB or larger USB key to your computer then launch the Mac App Store from your dock.