Word/Excel for iMac

The standalone version must be an updated version of Office2016 or later to run under OS 10.15. As 2016 must be updated before going on an OS v10.15 Mac, I strongly recommend skipping 2016 and going for Office 2019 if you do not want the subscription version. 2019 will install on a 10.15 Mac without any extra steps.

You can either buy a standalone copy of Office or you can subscribe to Microsoft 365. The choice is yours.

Look into the Free LibreOffice, it handles MS Office files…

https://www.libreoffice.org/