Also is it possible to use a credit card that's not in my name?
It will be tough, as most larger car rental agencies want you to be 25 or older and have x years of license; some allow below, but charge you through the nose for that. I cannot name specific companies that allow it, but probably the farther you go from big to obscure, the easier it gets. You will be able to find that info on the internet, together with prices.
You cannot use someone else's credit card. If the credit card holder is there (in person), he/she can rent the car, and add you as an additional driver (and he/she can then walk away and you drive all the time and return the car on your own)
Edit: if you go to some little hole-in-the-wall-rental, they might take someone else's credit card, but think twice before you drive a car from that level of shop.