BEST PDF APP TO USE

Acrobat Reader is just a reader and as such is one of the lesser complicated Adobe apps out there.

The app Preview included as a part of your OS is a good alternative. But, if you're looking for more bells and whistles, you'll have to learn the "complex" apps to get their full benefit.

Safari is a web browser and has nothing to do with .pdf files per se. Safari can be used to facilitate opening a .pdf, but all that does is point the file to the default app you've chosen as the reader.

I use Preview most of the time. However, some Government sites have "fillable .PDF" forms for you to download and fill out. Sometimes Preview does not handle fillable PDF files correctly – but Adobe Acrobat Reader does. In those cases, I'm very careful to always edit a file with Adobe Acrobat Reader, never opening it with Preview.