Dropbox has a "public" folder that will allow you easily drop files into it and then "Copy Public Link" and then simply add that to the Links module in the CMS.
Steps:
- Put the file into the Public folder in your Dropbox account.
- Right click on the file.
- Click "Dropbox."
- Click "Copy Public Link."
- Input that link into the "Links" module in your app CMS.
Other ways:
- Put the PDF online somewhere and use that url link in the "Links" module.
- Make the PDF an image (.png or .jpg) and use the "Slider" module in the CMS.