Do you already have another Hive account?
Hive.Blue free accounts are for users who do not already have a Hive account. Additional accounts can be purchased. https://signup.hive.io/
Do you have a Steem/Steemit account created before March 20th?
Good news! Your Steemit (Steem) account was ported to the Hive blockchain! Please use your existing STEEM keys to log into your HIVE account. It is a good idea to change your keys to HIVE. Should your account get compromised on either STEEM or HIVE, having different keys will prevent both being controlled by a bad actor.