My iPad is locked in activation mode

Turn off Find My iPhone Activation Lock - Apple Support

If you erase your device without signing out of iCloud first, it might stay protected by Activation Lock. Whether you erased your own device or bought one from someone else, you can turn off Activation Lock by entering the correct Apple ID and password.

Look here for help recovering your ID and/or password.

If you forgot your Apple ID password - Apple Support

If you bring it to an Apple Store with proof of purchase, they may be able to help.