the unlock code or your google password? If you enter the unlock code incorrectly a certain amount of times, it should ask you for your google account info. It's buggy though and may or may not work even if you enter your google login correctly. Only option after that is a factory reset.
You can let go as soon as the samsung logo appears. And note that this will restore it to an out of the box state and you'll have to sign in with your google account and redownload apps as if you had just purchased it. It won't wipe your sd card though.
I would like to thank the community members for responding with great solutions. If you are still having problems, please reply to the private message that I am sending you with your mobile number, your name and a contact number. I will contact you to provide troubleshooting assistance.