As written below, caravan parks often have accessible cabins and these are a useful option when travelling around Australia. Sometimes you need to ask, if you are booking ahead, as for some reason Parks often do not advertise their accessible cabins or forget to update their websites when they have added accessible options.
Try out this website for help booking accessible accommodation and maybe sign up for their newsletters.
https://www.accessibleaccommodation.com
A non-slip shower mat is always useful in your luggage (plus a towel to wrap up the wet mat if needed).
If you need a wheelie walker, consider purchasing a really light weight, collapsible one for your car when travelling (or even for at home to keep in the car).
A folding walking stick can also be easier to transport around.
There are also collapsible toilet surrounds and shower chairs and stools.