Adding a password to the admin administrator account
For security purposes one of the first things you should do is add a password to the admin account.
Depending on your firmware version, when you first log into the GUI you maybe presented with an option to change the admin account password.
From the GUI, access the Global GUI and go to System > Administrators, edit the admin account, and select Change Password.
From the CLI:
config system admin
set password <new-password>