Microsoft Office incompatibility with Catalina 10.15.7 on mid 2012 MacBook Pro

1. First, I upgraded my mid 2012 macbook pro operating on macOS Sierra to High Sierra (no problems with Word, Excel or powerpoint). Then, after reading that I could bypass Mojave and go directly to Catalina 10.15.7, I downloaded it with no problem; however, after doing so, I could no longer access Word, Excel or Powerpoint. It states that I must upgrade to use them, but when I try to, it says "can’t be installed on “Macintosh HD” because macOS version 13 or later is required." I'm caught in a loop; must do something, but not allowed to. As a teacher, the majority of my work is created in Word, Excel & Powerpoint. I can't even access my present worksheets for the students that I print out. PLEASE HELP Thank you!

[Re-Titled by Moderator]

Original Title: I just upgraded my macbook pro mid 2012 from macOS Sierra to High sierra, then Catalina 10.15.7. I had no issues with microsoft office in my High Sierra, but cannot use Office in Catalina. It says I need to upgrade, but can't. pls help