>>>>> Is there a way in which I can make it work again?
No way unless you will install one of supported macOS on your MacBook Pro - Apple® Mac® OS® X v10.11 (El Capitan) or Mac OS® X v10.10(Yosemite) or OS X v10.9.0 (Mavericks) or OS X v10.8.0 (Mountain Lion).
>>>>>Is there an update I can download?
There is no Update for AutoCAD 2014 for Mac for compatibility with macOS Catalina.
>>>>Or can I download the CAD onto a PC?
It depends on type of your AutoCAD for Mac licence. Theoretically you can use your license for using AutoCAD 2014 for Windows.