You can purchase prepaid visa/mastercards at most gas stations/convenience stores that are one-time charge but can't be refilled if you only have cash or a normal bank debit card that can't be used online, but you inevitably will lose a couple bucks that you can't spend once it's almost empty unless you remember to take it to a store and use the exact last bit of money combined with cash for the rest. They also have an activation fee, usually under $5. I get your struggle, I still don't have a credit card and I'm 27 lol.