There is no password needed.
If you are getting prompted to add a password or unable to print/edit, there are typically two troubleshooting steps that will fix the conflict.
1) Update your version of Adobe Reader. They make updates regularly. These updates sometimes trigger the password prompt even though one is not required. You can update your version for free here: https://get.adobe.com/reader/
2) Also be sure you are opening the file in Adobe instead of your default web browser.