The best place to seek work in the NSW South Coast (in the public sector) could be NSW Transport jobs: "I work for NSW". This below site is only an example [but inc.different non rail jobs and positions there in various NSW Govt sectors and sometimes far South Coast]https://iworkfor.nsw.gov.au/jobs/all-keywords/transport/all-organisations--entities/all-categories/all-locations/all-worktypes?divisionid=23&page=1
NSW Train Link advertise in this for Railway Station Staff occasionally at Wollongong or Southern Highlands/Canberra region.
If You really wanted to become a train driver either on the passenger trains (like Sydney trains; ie. an extensive course over 6 months) or a trainee freight train driver (with various or big organisations like Pacific National or Aurizon) best way is to check their websites.
Unfortunately you would have to be based in Sydney and regional or interstate positions. They also offer "ground crews eg shunters etc"
(but next to nothing on the NSW South Coast)
The "Fly in/out or 2 week rosters" are usually offered (only) to train drivers with many years experience & qualifications.
ie to drive heavy freight train haulage in remote areas of Aust.
I hope this may help a little in your search.