How can i unlock my ipad mini without apple id

Have you tried : If you forgot your Apple ID - Apple Support ? If you can find or remember your id, to reset its password : http://iforgot.apple.com

Or, and if you were the original purchaser of the iPad (i.e. it wasn’t bought used), you could try going to an Apple Store (make a Genius Bar appointment if you do) or try contacting iTunes Support online (https://www.apple.com/emea/support/itunes/contact.html) and see if they can remove the iPad from the account - they are likely to want to see proof of ownership before they might help e.g. original receipt with the serial number on it

You will need to remember them. THat is the activation lock and since it's mean to be a theft deterrent system there is no user work around.

The link below explains what it is

Find My iPhone Activation Lock - Apple Support