Hi thegreatoutdoors,
We understand you have some questions about two-factor authentication verification codes when you sign into your Apple ID, and we'd be happy to help.
To get started, we do want to let you know that the code would not be able to be used several times. For example, if you were to sign in on two separate devices for the first time, and at the same time, you would be sent a different verification code for each device attempting to sign in.
For more details on using two-factor authentication with your Apple ID, check out the links below
Security and your Apple ID - Apple Support
Two-factor authentication for Apple ID - Apple Support
Take care!