There has always been a lock screen on iOS devices. There's no way to get rid of it. The only aspect that can be changed is whether or not you need a password to unlock your device.
Go to Settings>Touch ID & Passcode>Turn Passcode Off.Sorry for not wording it correctly...yes, how do you turn off having to input a PIN
If you have any more problems or questions, don't hesitate to ask.AH got it, thanks!!