MS office for Mac

Hi

I have 2008 version MS Office installed from CD ROM that I purchased( but I misplaced it now) on my MacBook Pro ( 13inch mid 2010) with OS X El Capitan 10.11.6.

I have no problem using MS Office on this MacBook Pro now.

But I purchased newer MacBook Pro(13 inch 2017, two thunderbolt 3 ports) with mac OS Catalina 10.15.3.

After I copied MS Word on it and tried open it, I couldn't because it says something about 64 bits, 32 bits and OS names but I don't quite understand.

Anyway, Is there any way that I can keep using my old MS Office without purchasing MS Office 365 at $150.00 ?

Help me!!!

Thanks, Jason