If you've gotten your NetID, you've also received a letter or email from the Admissions Office or HR welcoming you to Creighton, this letter will contain your NetID, the URL to use, and instructions on activating your Creighton account.
The One-time password is just that, it is only good one time to activate your account. Account activation will create a profile which will allow you to provide alternate methods (cell # or email) to use to receive a code allowing you to reset your password if it is ever forgotten.
You must activate your account before you can log in to any Creighton resources. Using the Account Management Interface (AMI) , you can activate your account, set up your security profile, and create your Blue Password.