can i create a registration form, that allow my guest have unique account ID and pw

i want my guest able to login later, and change information later

If you are trying to create a sign-up or login form, this is unfortunately not possible with JotForm.  Since the forms cannot query outside sources, the forms would simply collect usernames and passwords, which is against our terms of use.  You can setup a form to collect details such as name, address, email address and other non-sensitive information.

Could you please provide us more information about your workflow? At that tine, we can assist more properly.

In addition to that, I see that you're asking password on your form.

I see that you're asking password and username in your form. I've deleted those fields Because of that reason, your account will not auto-suspended by our system. 

If you have any question or issues, please do not hesitate contacting us. We will be glad to assist you.h