Update from High Sierra

[helenand daniel]

I have a MacBook Air 2014 with 10.13.6 I'd like to upgrade my OS, preferably to Catalina 10.15
I can't see it on the App Store and don't know if I need to go to Mojave first? (I also don't see either of these listed in the available software updates on the Appstore)

 

[MightyGem]

Have a look here:

How to download and install macOS - Apple Support

Use any of these methods to download and install current or previous versions of the Mac operating system on compatible Mac computers. Each macOS includes the latest built-in apps available for that macOS, including Safari, Notes, Messages, and Apple Music.

support.apple.com

If you scroll down and click on the Catalina link, it should take you to Catalina on the App Store.

 

[helenand daniel]

Thank you. Done!