I would declare independence from NATO/Five Eyes, ally with China, remove US military bases from my country and then immediately change the date of Australia Day to 9/11 as a joke
I would then start de-desertification and other environmental projects, and start improving infrastructure too.
Ideally: End the wars, get rid of the CIA and FBI, Punish companies that pollute the environment much more, end reactionary policies, nationalize key industries, and form a plan for a transition to socialism, you probably can infer the rest
Realistically: Get shot in the head by a contact shot from some 4channer who gets secretly bailed out by the Pentagon as soon as I finish the oath of office, leading to the eventual collapse and Balkanization of the US over the next few months afterwards