Click the link labeled “macOS Catalina” under the heading “Use Safari to download macOS on your Mac” and follow the instructions.
In some cases there is an incompatibility between your computer and the newest version of the operating system. If that is the case, the installer will alert you to this issue when you attempt the upgrade. Please reach out to firstname.lastname@example.org if you encounter this error and we can work with you.
Catalina drops support for 32-bit apps. Before upgrading please make sure that the applications on your Mac critical to your work are compatible with Catalina. You can check this by clicking the Apple icon on the top left > About This Mac > System Report > Software > Applications > Sort by the last column (64-bit, Yes or No). If you determine you have important 32-bit apps, you may want to reach out to the software provider to find out what upgrade paths are available to use a supported 64-bit app.
Before upgrading, it is always wise to ensure that you have a complete back up of your files.
First, click the Apple logo in the top left corner of your screen and select About this Mac.
Click System Report.
Scroll down on the left-hand panel to find the Software section, and select Applications.
You'll find the affected apps in the far-right column, under the heading 64-Bit (Intel). Applications labeled with "No" are 32-bit only.