Nancy,
Just because you own a Mac, does not mean that you are required, or trapped into using Apple document formats. Word, Excel, and Powerpoint document formats can be opened by many different applications on multiple platforms, but Apple's Pages, Numbers, and Keynote document formats can only be opened on the Mac platform by these same applications.
Apple's applications are not MS Office application clones, so features that you have used in past Word documents, that Pages, Numbers, or Keynote do not know how to translate into Pages, Numbers, or Keynote features will be dropped. Any font references in those old Office documents that are not actually installed on macOS will either get converted to Times, or throw an error and not be replaced at all.
The advantage of using MS Office (Office365/Office 2016 for Mac/Office 2019 for Mac) is that you open the documents natively in their own formats, and can edit and save them without document translation issues on opening them, or exporting them — as you would have with Apple's applications.
There is the free LibreOffice (presently 6.2.4) that is a superset of MS Office that has the best Microsoft document compatibility outside of Microsoft Office. It too has a learning curve, and unlike Pages, Numbers, and Keynote, there are lengthy PDF user guides to ease the learning process. These user guides were all written in LibreOffice Writer.
The real strength in the Apple applications is the support they receive here in the Apple Support Communities from fellow users, though Microsoft as their own communities for their Office Suite applications.
