my school has annual camps for each year level and mine luckily isn't until later in the year but I am worried that I won't have been able to come out by then and even if I can I am worried the school will find a way to keep me on the boys side. also I thought I should mention I have a friend who is perfectly happy to room with me. so what I am asking for here is advice on what to do about getting my school to let me be on the girls side.
Tell them. Go to the head of year, or form tutor (or whatever you call them in Australia). Just someone who will listen to you, but have the power to talk to the people in charge. Alternatively, go straight to the person leading the trip and tell them. Tell them everything, if you can. Make sure to explain any terms, and I am sure that they will be understanding. If there is any Australian anti-transphobia legislature they probably can't stop you.