Once you connect to your new TS3 voice server, you'll notice that all of the admin options are grayed out. You can remedy this by using your TS3 token.
You would have been sent an admin token in your welcome email, you can enter it in the TS3 client by going to "Permissions" then "Use Token".
Keep in mind, the token is a 1-time use to set up the initial admin. After you use it, that account will need to set up the remainder of the users and assign permissions as needed.