There is NO solution to the Activation Lock!
There is no way to contact that original owner.
That iPad is a dead and useless device to you.
If you can, attempt to contact the seller that sold you this Activation Locked iPad and attempt to return this device and get your money back!
You will never get this device to work for you.
If no success with returning this iPad and getting your money back, then you are stuck with this useless device.
Please recycle this device responsibly.
In the future, If you must purchased used devices from unknown, untrusted sources, you must ask A WHOLE LOT more questions of the iOS device seller, ask for more photo/images, ask if the iPad has user/iCloud activation lock and ask for photos/images/short video proof, ANY REAL, UNQUESTIONABLE, UNMISTAKEABLE, CONFIRMED VISUAL PROOF, that such an iPad has been reset to factory settings and shown proof of the iOS device's start up screen showing the animated, moving, multi-language “Hello! Welcome to iPad” screen.
If the iOS device seller is unwilling to do all of this to show you that the iPad, in question, is ready to use with no barriers to new user activation and use, pass on the iOS device and look at other iOS device sellers, elsewhere, who will be more accommodating to answering questions and providing visual image or video proof of a proper factory reset iPad.
Sorry & Best of Luck to You!