Every time I refresh safari it says 'Your browser is looking a little retro... Sorry, but Apple Safari version 13 is no longer supported. Older browsers are slower, less secure, and don't support our latest features.' However, my MacBook is fully updated, and when I go into the App Store it says there are no updates. When I search how to update safari, it says it is automatically updated with macOS updates.
MacBook Air 13″, macOS 10.13
You don't say what model year of MacBook Air you have. The following may help:
The model year of a MacBook Air is available at Apple menu > About This Mac.
A late-2010 through mid-2011 MacBook Air can be upgraded to High Sierra 10.13.6 but no later version.
A mid-2012 MacBook Air can be upgraded to Catalina 10.15.7. See: https://support.apple.com/en-us/HT211683
A mid-2013 or later can be upgraded to the current version of Big Sur. See: https://support.apple.com/en-us/HT201475
You may be able to upgrade to Catalina with a little less free space needed than Big Sur -- but personally, I would deal the the lack of free space and upgrade to Big Sur.
It's a 2017 model. Does that help you to explain a bit more?
Also, if I don't have enough storage to upgrade to Big Sur, should I bother updating from High Sierra to Catalina?
Updating safari
