I have a legal waiver that I need people to e-sign. I'd like to attach it with a form;

How can I get the .pdf to come up for the customer to sign, while still sending with one submit button nd one form?

Hi,

You can display a PDF document on your form, just follow the instructions provided in this article: How to Display a PDF Document On Your Form. However, I am not really sure if the PDF E-sign feature will work on the suggested method above. I would suggest that you create the same content in your PDF in your form and add an Adobe E-sign widget to allow your user to sign your form. 

Do let us know if you need further assistance.

Regards.