Create a login system so they can complete the form at a later time?

I am trying to see if I have a long application if I can create a login to the form so they can come back and complete at a later time.

You cannot have a login system, as collecting login credentials is strictly against our terms:

https://www.jotform.com/terms/

However, based on your description, you can simply utilize our Save and Continue Later session saving method, which is described in the following guide:

https://www.jotform.com/help/227-how-to-enable-autofill-on-forms/

You will have one form as the starting form, where your users provide their email address and generate a session on the second form, which will be your primary form and where the partially filled out answers are saved each time they navigate through the pages of that form.

Please do take a look at the above linked guide for more details, and let us know should you need further assistance. Thank you.