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, or unless you can secure the cooperation of the previous owner, you’ll not be able to defeat or bypass the Activation Lock. Without documentary evidence that you are the original owner (such as sales receipt showing the serial number), Apple won’t assist - and nobody here will be able to help you.
Your neighbour, the owner of the AppleID that previously activated the device, will find the following information to be helpful with recovery of the forgotten AppleID or associated password. They will need to recover their credentials here:
https://iforgot.apple.com
To recover the credentials, you’ll need access to one of the following:
- The primary email address mailbox that corresponds with the AppleID
- Any of the secondary/recovery email addresses that should be configured for the AppleID account
- Any of the trusted telephone numbers (fixed line or Cellular/Mobile) that are associated with the AppleID
Unless the AppleID account has not been fully/correctly configured, or has been seriously neglected, recovery of the AppleID and password should not be difficult.
More information about recovery of an AppleID:
If you forgot your Apple ID - Apple Support
More information about recovery of an AppleID password:
If you forgot your Apple ID password - Apple Support
When access to credentials has been recovered, the owner would be well advised to log-in to your AppleID account from a web browser - and verify/update any email addresses and trusted telephone numbers:
https://appleid.apple.com
When the Activation Lock has been resolved, the iPad needs to be properly prepared for its new owner:
What to do before you sell, give away or trade in your iPhone, iPad or iPod touch – Apple Support