To update your Mac, you can follow these steps:

1. Click the Apple logo in the top-left corner of your screen.
2. Go to System Preferences > Software Update.
3. Wait for your computer to find the update and click Update Now.
4. Once the update is finished downloading, click Download and Restart.

After restarting, check that your Mac is running on the current software version. It is also possible to set your Mac to automatically keep itself up-to-date .