I need to find my iPad

You have no immediate reason to be terrified. Assuming that your iPad is protected with a Passcode, known only to you, your locally stored data is safe and beyond reach. Your iPad has a fully encrypted filesystem - that can only be unlocked/accessed with the correct Passcode.

As for your iPad being missing, start here:

Locate a device in Find My on iPad - Apple Support

Here is Apple’s advice for lost or stolen devices:

If your iPhone, iPad or iPod touch is lost or stolen – Apple Support

Use the Find My app to locate a lost or stolen device – Apple Support

If the Find My iPad feature was enabled prior to it being “misplaced”, then if active, you would stand a good chance of locating it. 

However, if the feature was not activated prior to being misplaced - or the iPad has been inactive for more than 24 hours, the last known location will not be available - and the opportunity to use technical means to recover the iPad may have been lost.

If you suspect that your AppleID has been compromised, or if you are particularly concerned, follow the advice outlined here:

If you think your Apple ID has been compromised - Apple Support

See the steps in here.

If your iPhone, iPad, or iPod touch is lost or stolen - Apple Support