As already indicated by Skydiver119, you may have purchased a totally unusable device...
If the iPad is disabled, you’ll need to follow this process:
https://support.apple.com/en-gb/HT211078
Here is Apple’s information about the Activation Lock - and how to switch-off this feature:
https://support.apple.com/en-us/HT201365
https://support.apple.com/en-gb/HT201441
As you will discover, if the iPad has been activated and associated with an AppleID account that you do not control, you will need to secure the cooperation of the account owner to whom the device is locked. If you cannot secure their cooperation, you’ll not be able to technically defeat or bypass this security measure. In this situation, there is nothing that anyone here can do to help.
If you are the original owner - and have documentary evidence (i.e, the original sales invoice that shows the device serial number), then Apple may be able to assist.
Sorry, this is perhaps not the news that you we hoping to hear.