I just upgraded to Catalina on my Mac and now it no longer supports Word. How to I reconnect Word to my Mac, using Catalina?

32 bit versions of Word, or any app, will not work on Catalina. You need to upgrade your Office to a 64 bit version. Office 2019 and Office 365 are 64 bit versions.

Two of the alternatives that John alluded to are LibreOffice and Apple's Pages, Numbers and Keynote.

Both can open MS Office files, read, edit and save them as MS Office files or in their own format.

Either continue to pay Microsoft, or consider this an opportunity to dump their products in favor of better alternatives. All are cheaper and some are free.