If that password box has the padlock, then you have the firmware password enabled.
That won't allow you to boot to a different partition, unless you know what that password isn. It does not have to be the same as your login password, and also not the same as your AppleID password.
Some will call it the "EFI" password.
As mentioned above, you might also have an MDM profile installed, which could also enable the firmware password. An MDM profile may be installed when you use your Mac for business (the company you work for might require that), or maybe your school would have set this up for you?
Are you the owner of this Mac? The status of the firmware password will be in Security Settings, when you boot to your recovery system. But then, you can't boot to the Recovery system, because that will also ask for the firmware password.
If you continue to see the padlock box, and you can't remember the password that you used to set that password, then you will need to contact an Apple Store, or contact AppleCare support for possible assistance with that.
(There's no other choices, unless you can remember the password that you would have used to set the firmware password. If you did not do the original setup on your Mac, you should also try to contact whoever did that original setup.) Good Luck!