Adding a conditional submit form…

I have a sign up form in use on my website that allows users to sign up for an event. In the form there are two checkboxes that affect the outcome of the form. If the first is checked, the amount they pay for registration is different than if it is unchecked. The second checkbox asks if they would like to pay online via PayPal, and if checked, submits the form to PayPal for payment. If it’s unchecked, they are taken to a page that shows the mailing address to send payment to.

Form would submit showing they owe $50

[ ] Already certified? (-$25 if checked, they would show proof of certification at the event)

[ ] Pay online with PayPal (if checked, sends the user to PayPal to pay either $25 or $50, based on the previous checkbox; if unchecked, sends to a page with details on where to send a check in to)

I’ve had this form in place for probably a decade on my old site, but as I’m having to redo the site without a coder, I have to learn how to do it myself. I have the basic form setup which sends an email, but I have no idea how to do the if/then statements or even how to send it to PayPal really.

I’ve tried a few different form plugins but none of them seem to work well with this style of if/then type statements…I don’t know how to code at all and am using the Headway WordPress theme for its visual editor. If anyone has any plugin suggestions I would greatly appreciate them.

Thanks!