This is a sample button.

To create a button you click on the plus sign on the left. Choose button from the pop up menu.

Click on any of the buttons there. It will appear on your site. You can click and drag it to any location you want. Next click on edit text and name your button. When you hover over the button a line of option appears. Click on the link icon. This will bring up a option menu. Choose document or website, which ever is the case. Then for a document click on choose file and upload media. Then upload form this computer. Your file must be exported to a pdf to work here. So have that done ahead of time. Click on your file from the drop down menu. After it loads, click on add to page. Then click on done. Last publish your site.