I have lost iPad

Unless you had Settings > iCloud > Find My iPad enabled on it then there isn't any way to try and locate it. If you did have it enabled you could try locating it either via http://www.icloud.com on a computer or Find My iPhone app on another iOS device - but that will only work if it's connected to a network.

You've reported it to the police (to get its serial number : Find the serial number of your Apple product - Apple Support) ? You should also change your iTunes account password, your email account passwords, and any passwords that you'd stored on websites/emails/notes etc., and if it was a cellular model also contact the carrier.