I am trying to find out if there is a special modem router that needs to be purchased for someone about to go online for the first time in an NBN connected area. Online chat disconnected me without answering the question.
It depends on the NBN Service Type being delivered at the address.
You can search at https://www.nbnco.com.au/ (just enter your street address) to identify NB Service Type
Then you can organise a modem asking for a compatible modem with the NBN service Type.