Can I ask for a payment before users can view my form?

2- We'd like to sell the access to the form. Can we have a payment process at the beginning of the form that will give access to the form once payment proceed ?

I'm afraid we don't have a feature like that here in JotForm but I can think of 2 possible workarounds that will let you achieve the same.

With a STAND ALONE FORM

If you won't be embedding the form on your website, then you can set up 2 forms:

1. Payment Form

2. Actual Form

The Payment Form is where you will ask for payment from your users using one of our Payment Processors. Afterwards, just redirect them to the Actual Form after making the payment.

Related guide: Redirecting-Users-to-a-Different-Page 

In case you're not sure which one will work for you, I recommend reading this article: Which-Payment-Processor-is-Right-for-Your-Business 

With an EMBEDDED FORM

If your form will be embedded on a page on your website, then this is something that you'd have to do outside JotForm. If I'm in your shoes, I will have my developer setup a page on my website asking for a payment before allowing access to the form.