As mentioned above. There is no way to know when an address has been created. An address with a valid checksum = a valid address, whether someone generated it with a wallet before or not.

As for your second question regarding a tool that finds addresses with fresh transactions, I'm not aware of any. I even checked some on-chain intelligence services but there's nothing of that nature. Obviously, that's doable but you might need to code it yourself. I'm curious, what is it that you're trying to achieve here?