I do not have a credit card, how do I remove content lock on ipad

Restrictions?

Settings>General>Restrictions

You don't need Credit Card, you need passcode.

Content lock meaning the restrictions passcode?

Yes you can remove it by restoring to factory settings and totally erase the device. That is the usual way to do it. I believe some third party apps let you get into the iOS files structure and claim to allow you to remove the passcode without restoring.

http://www.iphonebackupextractor.com/blog/2011/apr/7/how-to-recover-iphone-restr ictions-passcode/