Im wondering if I can use Jot form to give away a free PDF in exchange for collecting an email?

Yes, you can add a file as an attachment on each email notification to your user.

Please follow the steps here: https://www.jotform.com/help/393-how-to-attach-a-file-to-autoresponder-emails.

Please feel free to reach out if you have other questions or need some more help. I will be happy to help!