how do i upgrade my MacBook air (mid 2012) to a version previous to BigSur
i'm currently on high sierra and would like to upgrade a version such as Catalina. Where can i find this version?
MacBook Air 13″, macOS 10.13
Your MacBook Air 2012 can be upgraded to Catalina (10.15.7). See instructions in: How to get old versions of macOS - Apple Support