Someone sold me a stolen iPad

As described, the iPad is useless to you. Unless you have the means to independently trace the original owner yourself, unless the iPad is showing contact information on the screen, you have precisely zero chance of receiving assistance in tracing the owner.

Here are the Apple support pages that outline the Activation Lock - and the only mechanisms by which it can be turned off:

Activation Lock for iPhone, iPad, and iPod touch - Apple Support

Turn off Activation Lock – Apple Support

As you will discover, unless you are the owner of the AppleID that was last used to activate the device, you’ll not be able to defeat or bypass the Activation Lock. With documentary evidence that you are the original owner (such as sales receipt showing the serial number), Apple may be prepared to assist - otherwise they and nobody here will be able to help you.

Please don’t throw away the iPad. Instead, pleas return the iPad to an Apple Store for responsible recycling. If you don’t have a nearby store, Apple will send a prepaid shipping container free of charge.

There is no way you can contact the original owner or remove the lock. You could turn it in to the police, though it's unlikely that after a year there would be any attempt by the owner to retrieve it. otherwise recycle it.