Sorry matey, can't tell you how different it is from Australia, but can tell you that there are certainly opportunities to be had. The trouble is that they are usually fortuitous in nature.
Would not recommend you just arrive and hope for the best. Get yourself a plan for at least six months to a year. The US is a very inhospitable place to be when life does not go as planned.
I am lucky enough to be able to live and work over here. I love the flying, but don't enjoy the lifestyle so much. I would have another plan to beat it back to to Aus if things did not work out as planned so keep any bridges you may have firmly in place.
Good Luck.