How can I complete a section of a form before I send to customer to have them finish completing their information?

I want to start each form with individual customer information then have the customer complete additional product questions and return to us. 

If you want to send the form partially prefilled, you can do it through the Field Prepopulator app: https://apps.jotform.com/app/field_prepopulator 

Let us know if you need more help.