Take leave. Drink beer. Forget about studying for awhile. There will probably be three NATOPS changes between now and when you class up anyway and you'll have plenty of opportunity to learn the jet when you get here. For as complex as the Growler is, the basic fam/form stuff is pretty easy to learn. Plus, the earlier you get here and check in, the earlier they can schedule you for fun stuff like FOD walk down and command PT.