Nice... But seriously would they bring me in or issue a fine?
Years ago, you would get told to park the bike and walk.
These days.. the vehicle gets impounded and the person arrested.
That's the usual outcome, although it might be different for someone who is under 18.
I can't see them issuing a fine.
State governments got very serious about the whole unlicenced driver/unlicenced vehicle thing in the mid to late 2000s.
I'm not a lawyer, so I'm speculating. I would have thought that it would likely be an arrest, and very much most likely vehicle impounding.
Call the cops and find out. Ask what laws you would be breaking, download the legislation from the relevant government web site and read into it.
In WA, it's the State Law Publisher - State Law Publisher - Western Australia As you're in NSW it will be a different web site (ie similar).