Pages & Numbers
Mac Pages and Numbers will no longer update. State they need Mac OS v10.14 to update and my latest software update is v10.13.6.
MacBook Air 13", macOS 10.13
Pages v8.2.1 and Numbers v6.2.1 require the installation of either Mojave or Catalina for their own installation from the Mac App Store. If you cannot upgrade your operating system because your iMac is older than 2012, then you are stuck with the Pages and Numbers versions presently installed.
From menu : About This Mac, what is inside the parenthesis on the Mac model description line (e.g. Early 2014, etc.). That string will be the determinant if your MacBook Air can upgrade further. Essentially if that parenthesis shows 2012 or later, you can upgrade to Mojave, or Catalina from the Mac App Store, and either are the requirement to install Pages v8.2.1 or Numbers v6.2.1 from there too.
If you presently have considerable 32-bit applications (e.g Office 2011 for Mac, printer/scanner drivers, etc.) then these will not run on Catalina which requires 64-bit applications and drivers — which may or may not be upgraded to 64-bit compatibility with Catalina. You may be better off upgrading to Mojave which can still support 32 and 64-bit applications.