Mr Sham has a good point. Even if you have been in the US for enough days to adjust your sleep schedule from OZ, you will be thrown into a sleep-cycle blender of being at about 4000' altitude, a disruption in eating times, ultra-bright sunlight trying to set your body's clock, and wanting to do all the night-time things. So that makes it hard to volunteer for a specific shift in advance.
You can go to Playa Info in Center Camp for ad-hoc volunteer opportunities when you get settled.
The main BurningMan.org website is exellent reading including
https://burningman.org/event/participat ... irst-time/
Welcome to ePlaya and your first burn!
If you are coming all the way from OZ, the Western US is a fine walkabout of national parks and wild lands, gnarly mountains, fierce rivers, and hot springs, with many fine cities in between. Fuel prices will probably continue to be high, and rental vehicles are in short supply because all the rental companies sold their vehicles in the Covid recession, and are having trouble buying new ones. Nonetheless travel around the US is a great opportunity!