iPad activation error

Are you trying to activate the iPad by itself? Or with iTunes on a computer?

A) If you are activating the iPad by itself (you only interract with the iPad) :

Ensure you have a valid Wifi connexion. Maybe the network you're connected to has restricted access to Apple activation servers so try another Wifi network if you can.

If the issue is still there, try with iTunes.

B) If you are activating the iPad with iTunes (the iPad is connected to a computer with USB cable) :

Ensure you have the latest version of iTunes installed (https://www.apple.com/chfr/itunes/download/)

Ensure you have a valid internet connexion on your computer and try with another connexion (ex. iPhone connexion sharing) if you can.

Try to put the iPad in recovery mod (https://support.apple.com/en-gb/HT201263) and update iOS if asked to.

If you forgot your Apple ID - Apple Support

If you forgot your Apple ID password - Apple Support

What iPad do you own and what is the exact message you are getting?