Can we get form data when using paypal?

This is our first paypal integrated form.  We want the customer to complete the form and go to paypal for payment.  We have to be sure we get the form data they submit, and they're not just paying for something and we're totally unaware.  

On this form, will we get the form data after they hit submit and pay in paypal?

Yes, you'll get the data right after someone completed the payment through Paypal. In the email/submissions page, you'll also get the Payee Name and Address details aside from the product details in the form.

Please note that if someone won't complete the transaction, the particular submission will be added to your incomplete payment list. To know more about this thing, please check this guide: https://www.jotform.com/help/272-Paypal-Incomplete-Payments-FAQ.