I am almost 15 years of age and am wondering about ways of paying for services

I, being a legal minor, have read the terms of service (to the best of my extent) and have found no issues with my age on this service, and due to this I am wondering how I could set up a payment system of which I could use a chain of prepaid cards I have acquired to pay for my usage. I currently have no other means to pay actively but if anyone has an idea of how I could set this up without an official bank account that would be truly grateful!