So I downloaded the app as i was thinking of buy some bitcoin which made me think, "if i buy say, $100 worth of bitcoin with a credit card (or wtv) where does the bitcoin come from? Who's providing it?"
Especially if blockchain.info is just a wallet.
Anyone know?
You bought from a person's wallet, not from the blockchain. The blockchain provides the rewards for block finders and that is all. There are plenty of sites that can give you the easy bitcoin lessons, this is very beginner stuff.