CTA Intent – Complete the present task or proceed to future task?

I want to understand the real motive of CTA. Call-to-action, as it abbreviates, is it the action to be performed based on the present context or is it based on the future action that will have to be performed?

For e.g. I am on a product confirmation page and next page is the payment page. What should be the CTA on the confirmation page/Which would be a more appropriate CTA? Confirm or Make Payment

If in case of Make Payment, what should be the CTA on payment page?

Edit: I am in an organization that helps its users to set up "Systematic Investment Plans(SIP)". When they have input their investment amount, investment duration and the fund to invest in, the next step will be payment. In this case, which would be more appropriate CTA, Setup SIP or Proceed to Payment?