How can I integrate paypal payments processing?

I am finding it difficult to ativate paypal pro for payments processing. The form keeps saying that I should disable the payments processor already setup. I am not aware I did setup any one.

Furthermore, on the website that has this form, once I complete the form and say submit, it returns an error message rather than directing to a payment page.

Kindly assist

I have tested your form and I was able to submit it without any problem: 

I can see you currently do not have an integration in your form, but seems like you're trying to set up more than one payment method in the same form, you cannot add more than one payment integration to one form, to achieve this you will need to follow a method where you will embed those forms in one main form.

Here is a guide with more details about how to set up a multiple payment form: How-to-Create-a-Basic-Multiple-Payment-form

Hope this helps.