This would indicate that the iPad was not correctly prepared prior to being sold to you - and is still associated with the previous owners AppleID. Unless you can secure the cooperation of the previous owner, you’ll not be able to reactivate the iPad for your use.
The Activation Lock cannot be bypassed. Other than us being able to direct you to the correct procedures, we cannot help you. Unless you are the owner of the AppleID used previously to activate the device, Apple will not assist.
This is the process that should have been followed to prepare the device for reuse by a new owner:
https://support.apple.com/en-gb/HT201351
Here is Apple’s documentation concerning the Activation Lock and associated procedures:
https://support.apple.com/en-us/HT201365
Whilst I appreciate that this information may not be what you were hoping to discover, I hope that it is at least helpful in explaining your situation and potential ways forward.