If I integrate a payment option will the existing submissions include payments also?

I didn't realize the CC#'s wouldn't show all the way and I have 82 orders I need to process. It doesn't show all the numbers since I didn't sign up for a payment thing. I didn't know I had to. If I integrate them, will it show me all the info they already plugged in or will they have to each go back and fill out the form again? Thank you

No.

If you only added Payment integration after, previous or existing submissions will not have the payment details (i.e. credit card account details) on them.

You will need to have the previous form respondents re-submit the form again with the Payment integration added an your form this time.