how to create or alter submission forms in abantecart

[DavidLIR]

How can I create forms through abantecart 1.1.7?  for example, I have used jotform.com to create forms for email submissions, and various other kinds of forms.

I see there is an newsletter submission form built into the abantecart, however I would like to be able to edit that to add a checkbox for someone to choose to enter our monthly drawing for a free item. and to change the name from Newsletter sign up to something different.

I saw reference to flexy forms...don't know what this is, or how to

So really 2 questions:
1) how to build a form from scratch for submissions?
2) how to edit the Newsletter form on the cart

Thank you for any help...
David