Driving round Australia is safe but there are a few things to take into consideration.
Across northern Australia you will encounter road trains. If the road is narrow and there is a road train coming towards you, slow down and move onto the shoulder. Allow the truck to have the bitumen. You will save lots of windscreens doing that. If the road train is ahead of you and you want to overtake and the road is narrow, you will have to do your overtaking on the shoulder. You do not want the road train in the dirt flinging up clouds of dust. The most important thing before you start any overtaking manoevre is to make sure the road train driver knows you are there. Pull out and drive so you can see his mirrors and he will be able to see you. When you start the overtaking, flash your lights to let him know. Most roads, however, are wide enough so you can overtake safely with both of you on the bitumen.
Many roads across the north are unfenced. There can be cattle on the road. If you don't have a clear view of the road ahead, slow down. Don't drive at night unless you have to as you have kangaroos to contend with as well as cattle. If you do have to drive at night, drive at a reasonable speed so you can stop quickly.
Every town and village and most national parks have camp grounds. You will have no trouble finding somewhere to camp.
One general rule for traveling round Australia, whether by car, boat, plane or penny-farthing, is that the prevailing winds are easterly across the north and westerly across the south which means you will have more tail winds going anticlockwise than clockwise. Over the 20,000km or so of the entire circumnavigation, that gives you quite a saving in fuel.