The only tracking feature Apple offers is the one tied to your iCloud account (https://www.apple.com/icloud/features/find-my-iphone.html). If you did not have an iCloud account set up on the iPad, or did not have the "find my iPad" setting enabled under that account's settings, then you cannot track it remotely.
There is nothing you can do but hope the police do something, or you find it yourself. Apple does not get involved with lost or stolen property.
However, I hope you IMMEDIATELY changed your AppleID password when you noticed the added email - the only way someone could do that is if they know both your AppleID primary email address AND your current password.