First of all, beware of buttons in PDFs. While Adobe Acrobat can use them, if your user opens the PDF in other apps, such as Preview on Mac, for example, they won't work. If you really need a PDF with buttons, use Text Anchors instead. Or move to a platform that supports specific pages, such as Publish Online. Some examples: https://adobe.ly/2yTI8OE
Yes, totally agree with Derek, use hyperlinks instead when you simply want to go to a page. The PDF version of the sample file I posted is set up with hyperlinks on the arrows that go to the next/previous page, as a simple example.