How can I see and remove encryption on iPad?

What, precisely, is the problem that you are attempting to resolve? Be aware that with the sole exception of your locally stored Photo Library, your iPad/iPhone does not expose its filesystem to USB connected devices - and only then after the device has been unlocked with the correct Passcode.

Your iPad uses an encrypted filesystem. By design, unless you are able to successfully power-on the iPad such that it is running normally - and you are able to enter your passcode - all locally stored data will remain encrypted and and cannot be accessed.

iOS/iPadOS filesystem encryption is completely transparent - it is always enabled.

What kind of encryption did you turn on? iPhone contents are always encrypted, and there is no way to turn it on or off.