How do I upload a pdf form?

Are you planning to have your users upload a PDF file? If so, then please use the "File Upload" tool under Form Tools.

If you are planning to embed a PDF file on your form, then you can use this PDF Embedder widget or the Iframe Embed widget. However, you need to upload the PDF file first to your web server.

Related guide:
Upload-Field-Allowed-File-Types
How-to-Add-a-Widget-to-your-Form

Hope that helps. Thank you.