Hi Kristin - welcome aboard.

Not sure about loads Southbound from the U.S. to Oz in October, but you shouldn't have any problems getting back from here to there at that time of year.
You didn't mention which carrier you are with, so I'll throw out a few different suggestions for you.
CO - flies 3 x weekly GUM-CNS with AirMike.
QF - flies up to 7 daily LAX-SYD/MEL/BNE/AKL & 3 times weekly HNL-SYD.
UA - flies 1 x LAX-SYD and 1 x SFO-SYD daily.
NZ - flies several daily LAX-AKL & SFO-AKL. From AKL untold options across the ditch into Oz.
AC - flies 1 x daily YVR-HNL-SYD.
HA - flies 4 x weekly HNL-SYD.
There are other untold options via the Far East or Asia as well, including JAL serving both SYD and CNS. There are not a lot of options to/from CNS on international routes so you may need to backtrack to/from SYD or BNE. Internally, QF flies almost everywhere, however a lot of their leisure destinations (like CNS) have been handed over to a low cost subsidiary Jetstar & interline rates/zed's do *not* apply.
I would check virginblue.com.au, jetstar.com and qantas.com to get bargain revenue ticket deals to travel internally.
Cheers.