iPad Pro serial number
Can I enter my iPad Pro’s serial number on Apple’s website to find my purchase date?
iPad Pro 10.5-inch, Wi-Fi, Cellular
Question marked as
No, it generally does not show an exact date except to say it is covered by warranty/Applecare - or not. You can find it on your purchase receipt or, if it was within the last 18 months, it should be under your purchases in your Apple ID/iTunes account.