computer software

Microsoft does not sell products that continue to work forever into the future. Office 2008/2011 are 32-bit Office suites, and neither are supported on Catalina, or by Microsoft. If you want to continue using Office on Catalina, you will need to decide whether to subscribe (Office 365), or purchase a perpetual license (Office 2019 for Mac). Even if you did the latter, at some point in the future, it will no longer be compatible with changes in macOS, and/or Microsoft will retire it too.

Or, you can download the free, 64-bit LibreOffice Suite which will allow you to open/edit/save your existing Word documents.

Yes, you need to upgrade to 365 or Office 2019 to be compatible with Catalina.

https://products.office.com/en-us/compare-all-microsoft-office-products-b

Use the link to upgrade.

Yes, as I said. Your version of Office is 32-bit and Catalina cannot run it. Either upgrade or try using the free LibreOffice:

https://www.libreoffice.org