Hello!

WordPress will let you upload a PDF just like an image using the media manager. If you import it to the post, it will create a link, or you can link it yourself using a button or icon or whatever you like.

There areplugins that will let you embed PDFs in the page so it displays inside your theme and from there the visitor can choose to full-screen it (best option)

Here is one tutorial from WPBeginner that explains in more detail:
http://www.wpbeginner.com/plugins/how-to-embed-pdf-spreadsheet-and-others-in-wordpress-blog-posts/

If you want to do something like have a page that holds the title and featured image, but then opens a PDF when the page permaink is clicked anywhere on your site, you need a plugin like Page Links To to create the redirect by adding a custom URL to the PDF file from the page. That custom url essentially replaces the page’s permalink everywhere.

Buttons are created with the button element in HTML, or with the button class in a link. For styling options, see our button page in the framework reference here:

https://docs.layerswp.com/layers-framework-buttons/

Example:

<a class="button" href="link"> Link Text </a>