Unless you enabled Find My iPad on it before it was lost/stolen then there isn't any way to locate or send a remote wipe message it. If you did enable it then you could try locating it either via http://icloud.com on a computer or Find My iPhone / Find My iPad on another device - but that will only work if it's connected to a network and the device hasn't already been wiped and/or Find My iPad disabled on it.
If you think that it was stolen then you should report it to the police. You should also change your iTunes account password, your email account passwords, and any passwords that you'd stored on websites/emails/notes etc.
These links may be helpful.
How to Track and Report Stolen iPad
Reporting a lost or stolen Apple product
Report Stolen iPad Tips and iPad Theft Prevention
How to recover a lost or stolen iPad
How to Find a Stolen iPad
Apple Product Lost or Stolen
Oops! iForgot My New iPad On the Plane; Now What?
If you don't know your lost/stolen iPad's serial number, use the instructions below. The S/N is also on the iPad's box.
How to Find Your iPad Serial Number