so…after WWII the US gave financial aid to all those countries and stuff…does that mean that the US gave the money away for free? or do they owe us something?

The Plan involved cash grants, mostly for the purchase of US-made goods. There were a number of restrictions to help ensure that the recipients couldn’t compete with the United States.

Yes, the money was "free" in the sense that it wasn’t a loan, didn’t generate interest, and did not have to be paid back. And no, they don’t "owe us something."

By the way, the United States had a "Lend-Lease" program before the war, and the beneficiaries were supposed to pay that back, but they never did.