Hi and welcome to iMore!
Touch ID is available on the iPhone 5s, 6 and 6 plus, as well as the iPad Air 2 (not the first iPad Air) and the iPad Mini 3.
I'm not sure what you mean by "The thumb print place." My apologies. If you have an iPad Air 2 with the Touch ID system, merely putting your assigned digit onto the Home button should unlock your device. If it is an iPad Air 1 without the Touch ID then obviously it won't open with a fingerprint..
If you have forgotten your passcode then unless you remember it, or can unlock with a fingerprint (if eligible), you are going to have to restore it through iTunes.