Find my iPad has found my iPad. Now what do I do?

Use the Find My app to locate a missing device or item - https://support.apple.com/HT210515

"What happens if you activate Mark As Lost

Mark as Lost remotely locks your missing iPhone, iPad, iPod touch, or Mac with a passcode, keeping your information secure even if your device goes missing. You can also display a custom message with your phone number on the Lock screen, and keep track of your device's location.

Once Mark as Lost is activated, Apple Pay is disabled, if you have it set up on the device. A confirmation email is sent to the primary email address associated with your Apple ID. When you recover your device, you will need to unlock it with your passcode."

Did you add a custom message, preferably one with some neutral contact method such as a toss-away email address that automatically forwards to one you usually use? I only say this because if it was a thief who ended up with it they would love to send you fake messages from "Apple" inviting you to log into bogus web sites so they can get your log-in information and then they can use your iPad, plus maybe your Apple ID too. On the other hand there is a remote possibility some well-meaning person did end up with it and you stand a slight chance of getting it back. Just be careful.

You provide no background to this. If it was stolen, call the police. If you forgot it at work and it says it is where you work, go to your office and pick it up.