To be able to log in to your new server you need an account.
It is recommended to use security level 3 for your own account.
account create <user> <pass>
account create admin admin
account set gmlevel <user> <level> <realm>
account set gmlevel admin 3 -1
Note: (-1 for the all realms)
account set password <user> <password> <password>
account set password admin 1234 1234
The highest security level is SEC_CONSOLE (4) which your worldserver has by default.
It has access to account management and is not recommended for in-game accounts for anyone that does not know what they are doing.
To update an account to security level 4 you need to manually edit the fields in the database or run the query below.
UPDATE `account_access` AS `access` INNER JOIN `account` AS `account` ON `access`.`id` = `account`.`id` SET `gmlevel` = 4 WHERE `username` = '<user>';