How to recover Preview password?

Preview doesn't make passwords.

If you find that a pdf file has a password, then check with whomever provided that file - usually the owner or creator.

Password-protect a PDF in Preview on Mac - Apple Support

fredrick181 wrote:

Thank you for responding. I created the doc from a ca.gov website. So does it get locked from their end when I sent them the form?

Yes, a pdf from a government site may well be password secured by the sender and require that pword at your end to open and view it. This is especially if the pdf might contain private information.

Contact the sender and ask them to clarify and provide the password. You might also carefully read whatever email may have been sent with the pdf. Often the guidance for opening those will be contained in that email.