Who was the first to discover mint?

Answer 1

No one "discovered" minted coins. "Discovering" implies that the coins were already made but hidden somewhere and someone found them while exploring.

If you're referring to who first developed the process of minting coins, that's been traced back at least as far as the 5th century BCE when various Greek city-states created coins by hammering bits of gold, silver, and other metals with dies that imparted a design.

There is also evidence that the Lydians produced coins as much as a century earlier than that.