 You can use Ubuntu 18.04 with Ubuntu pro for next 5 years free of cost for non-commercial purposes, Ubuntu 18.04 flavours will also work but no support wi be available for tge flavour related components (re @Bracho_desu: Where can I find a 32bits version of lubuntu?)
 You can use latest version of software through flatpaks etc. (re @BlackKnight987: You can use Ubuntu 18.04 with Ubuntu pro for next 5 years free of cost for non-commercial purposes, Ubuntu 18.04 flavours will also work but no support will be available for the flavour related components)
 Maybe Snaps also (re @BlackKnight987: You can use latest version of software through flatpaks etc.)
 While it is true you can install 18.04 and enable Pro, it is not recommended nor supported by the Lubuntu team since it does not cover the desktop components like you mentioned. (re @BlackKnight987: You can use Ubuntu 18.04 with Ubuntu pro for next 5 years free of cost for non-commercial purposes, Ubuntu 18.04 flavours will also work but no support will be available for the flavour related components)
 There are >65000 packages in bionic, Ubuntu Pro according to the release blogs provide support for >30000 packages; ie. only a portion of the total packages, and that has never been for all architectures. i386 support ended 30-April-2023 with no Pro support available  (the extension to 31-May-2023 only mentioned architectures supported by Ubuntu Pro). Run `ubuntu-support-status` on a i386 & check; explore apt-cache pkgnames & contrast w