Q: I can not contact the owner who sale me the ipad but did not unlink it from his apple if now how I can actiate it without cobtacting the owner that I do not know how to see again.

Hi

You are describing Activation Lock, which is designed to prevent unauthorised use of an iPad if it is lost or stolen.

Unless you can arrange for the previous owner to follow the steps in the following support article, you should return the iPad for a refund or exchange, as there is no way around this security feature.

More information:

Turn off Find My iPhone Activation Lock - Apple Support

I can not contact the owner who sale me the ipad

I'm sorry, but this circumstance there is nothing you can do. You will not be able to use the iPad and there is no way whatever round this.