How to check purchase date for Apple devices

The only way to get the exact purchase date is through your original receipt.

However, if want to see if there's warranty coverage on it, you can enter the serial number here.

It's generally a good idea to keep the receipt and once the MBP was up and running, make a calendar entry, or reminder note to show you when and where you bought it/and the price you paid. That would give you a good idea when the warranty runs out if it was bought new. I suppose that if you bought it on Amazon or Ebay, then you could trace your orders or purchase history there.

Is it very old, and was it bought new?