I think you need to go to your nearest Samsung Service Center for that, or try to call them first and inquire about your fingerprint sensor needs calibration
Did you try restarting? If not try restarting the device and also try removing the fingerprint and adding it again if you cant add a fingerprint it means there's a problem on the sensor and also if you add and it was successful try opening your device again using the fingerprint if its still not working try contactibg the samsung via live chat, email, phone or going in a samsung service
