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 have been lost.
As you query suggests, a WiFi Only iPad may be unable to connect to WiFi networks that were not configured by the owner. However, for recent models of iPad with iPadOS15/16 installed, Apple’s Find My network goes further than just a network connection over WiFi or Cellular…
It is impossible to fully disable the iPad’s Bluetooth radio - and all Apple devices privately/anonymously communicate via Bluetooth beaconing; every device “listens” for other devices - effectively participating within a meshed network of tens of millions of devices. As such, another device can detect another - and report the detection along with its own location. For example, a passing iPhone will report receiving a beacon from your iPad - and send the approximate location of the iPhone; as the iPad must be within ~30m (30’) of the detecting iPhone, its location is known.
