Hide calculation field

Also am I able to have forms emailed to me regardless of whether customer signs up on go cardless? Currently it’s the calculation and then they click next and it shows the go cardless price. I would like to skip the calculation bit and show prices for every 4 weeks and every 8 weeks 

By default, for as long as the form is submitted, you should be able to get the notification email regardless of the content.

To ensure that your users can submit even without filling out the payment field, make sure that the payment field is NOT required.

How-to-Set-a-Field-as-Required-or-Non-Required

As for the calculation fields, you can hide them by following this guide:

How-to-Hide-Form-Fields