I am trying to open a file from ancestry.com and it appears that I don't have an application, which looks like it is adobe reader, which I have but according to what I have read my Mac Catalina doesn't support it?
32 something versus 64? I have no idea.
Does you open the file in Acrobat Reader or in a web browser?
Catalina and the current version of Acrobat Reader work together just fine. But Catalina already has a PDF reader too. May be more to it than that.
The PDF Reader built into Catalina is called Preview, and you don't have to download it. It's not as good as Acrobat Reader, but it mostly works.
HOWEVER, you should not be getting any messages about "not having an application" for PDF files. Does it definitely say it's a PDF?