You NBN-FTTC install is progressing.
Your installation class involves an NBN tech visit and he will supply you with the NCD.
He should could connect and test the NCD to the socket in your house.
You can plug your modem in but it may take a further 24hrs for the provisioning to completed before the service will work, or it may work straight away.
You may check the setup guide that we've created for NBN-FTTC here.