By default, PDFs will open on your Mac in Preview.  Try the Acrobat Reader instead.

• download it for free from https://get.adobe.com/reader/.
• Locate the PDF file in Finder and click it once to select it (but don't open it).
• Choose File > Get Info (or press Command + I).
• Click on the Open With drop down menu and choose Adobe Reader from the list of apps on your Mac that can open PDFs.
• Click Change All.