Credt Card/Mastercard help? ._.?

Ok so I looked up a few things and it’s required to be 21 to get a MasterCard.
All I really need is a credt card to buy things online, and recieve money via Paypal. (I get paid via the internet Via YouTube)
Is MasterCard the only way or are there others?
P.S. I don’t wanna wait intil 21 to get a MasterCard.
Also, I currently have a bank account/savings account.
Alright, but you didn’t have to be such a dick Calvin.