❗️ Do NOT upgrade until you have made a Time Machine or other backup of your startup drive.
Learn How to Back up your Mac with Time Machine
How to Upgrade macOS:
The macOS version you can upgrade to depends on the year your Mac was released.
Click the (Apple) menu at the top of your screen and choose About This Mac.
Check the Compatibility of your Mac with newer versions of macOS:
➡️ macOS 10.14 Mojave is compatible with the Macs listed here
➡️ macOS 10.15 Catalina is compatible with the Macs listed here
➡️ macOS 11 Big Sur is compatible with the Macs listed here
➡️ macOS 12 Monterey is compatible with the Macs listed here
❗️ – IMPORTANT – Your 32-bit apps won’t work in Catalina, Big Sur or Monterey.
https://support.apple.com/en-us/HT208436
Use the free utility Go64 to check the compatibility of your apps:
https://www.stclairsoft.com/Go64/
✅ - IF your Mac and apps are compatible, then using Safari only, download the macOS upgrade installer app:
Click > Mojave, Catalina, Big Sur or Monterey.
Once downloaded, double-click the “Install macOS…” app in the Applications folder to begin the upgrade.