If you add a PDF to Zotero it will try to retrieve the metadata about the PDF and turn it into a proper item in your library. This works for most academic PDFs. One way to do it is just to drag the PDF onto Zotero.
Zotero's support page has links to all the documentation.
Search the Zotero forums to find answers to common questions, or to submit a "New Discussion".
For more options and answers to common problems, go to our Ask & Services.