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As the Find My feature was clearly activated prior to loss, the iPad will be protected by its Activation Lock. If the iPad is reset or erased, the iPad will be rendered useless to anyone other than you.
Here is Apple’s advice for lost or stolen devices:
Locate a device in Find My on iPad - Apple Support
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 or without an active network connection for more than 24 hours, the last known location may not be available - and the opportunity to use technical means to recover or remotely manage the iPad have been lost.
Nobody can gain access to your iPad without successfully entering the correct device Passcode - and for this, there are a limited number of tries before the iPad will automatically become disabled. As such a brute-force attempt to access the iPad, by guessing the correct passcode, is highly unlikely to be successful. Only if your device Passcode is known to whoever finds your iPad will any locally stored data be at risk of discovery.
iOS/iPadOS is architecturally designed to protect the owners data.
All locally stored data is encrypted; by design, the only copy of the encryption keys necessary to access local data are held within the Secure Enclave - the device security chip. The device Passcode unlocks the Secure Enclave, which in turn releases the encryption keys to the Operating System while the device remains unlocked.
If an incorrect Passcode is repeatedly entered, the Secure Enclave automatically wiped and the device disabled - an operation that erases all stored encryption keys. This is known as a crypto-erase. Once erased, all locally stored data is permanently beyond reach and cannot be recovered.
