can't find my iPad

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

Facilities to manage/recover a lost or stolen device are predicated on Find My iPad being enabled on the device before it was lost.

Use any internet browser and log into www.icloud.com/find

Other information in: If your iPhone, iPad, or iPod touch is lost or stolen - Apple Support