Unless there is an NBN box already installed in your place there is not much you can do with the modem but wait for the technician to come and connect the place to the NBN. Once this is done you can then connect the modem to the NBN box.
What you could do meanwhile is connect your PC to the modem via a cable to one of the RJ45 ports and log in to the modem and configure it with your account name and password. From memory that's all you'll need to do to get connected to TPG over NBN once you are connected to the NBN.
How long is the wait? I guess that depends and if NBN is involved, the wait can be longer if only TPG is involved. In my case, it was a new NBN installation, and TPG did not have to come to my place. I think that every thing was done within a week or two from the moment I signed up.
My FTTB install went as follows... skip to the part after i signed up and received the modem:
Call TPG to have a tech sent out
They will advise of next available date
The tech appointment are either morning (8 am - 12 pm) or afternoon (1 pm - 5 pm) - times are estimate
You can ask for a call on approach - the tech will call you 30 mins to an hour before they get to your place
Tech will go to MDF in your building to patch the FTTB wiring
Tech will check the phone line works in your MDF and home phone socket
Normally the modem is preconfigured with your TPG details, if not its good to have your TPG login handy
Usually your FTTB will be setup and working before the tech leaves. It takes around 30 mins to an hour for tech visit. Mine took 15-20 mins cos no major issues