Does anyone know if it is possible to pull the metrics from an pdf that has been created?
If Download link is tracked correctly within Adobe Analytics, you can refer to Download Link Instance metric in the report against Download Link Dimension.
If I have understood correctly, you want to track the data in Analytics from the PDF file. This is possible only if you have few links in the PDF file which when clicked are taking the users to the web site where the Analytics is implemented. For example, let's say I have a PDF file with the link https://www.test.com which has Analytics implemented on it. So, if any user clicks on the link then the link will open in a browser where Analytics server call will get fired. So, in this scenario, we will be able to track the data for this link in the Analytics report.
Hope this helps. Please let me know if you have any further questions & I will be happy to assist you.