From: Brussels, Belgium
The advice I’d give, before going all in with issuing orders everywhere, is : start a campaign on a light-mode. Don’t worry about building bases, moving many units, organizing all the convoys. Let the turns run, to see the pace of things, the scope of the full campaign, etc.
If you do full turns, and go back on a previous turn when something went wrong, you’ll throw dozens of hours of game for mostly nothing. At start, a turn will ask 2 or 3 hours, maybe more (and certainly more for the first one), with a lot of clicks which don’t require much thinking. If you go back only one turn, and you remembered to save the turn after your orders, you’re okay, you didn’t lose much. But if you have to go back 2 or 3 turns, because changing the orders for one turn doesn’t allow you to avoid the catastrophe, you throw away several hours.
So, don’t worry, do a couple dozen turns without pressure, knowing you’ll start again, just to see the pace of the Japanese advance, how the battles evolve in Malaya, the Philippines, China, your first losses to the IJN submarines. See the time it takes to bring a TK convoy from Los Angeles to Sydney, how many cargoes you have overall, where your unrestricted combat units are. This is the kind of things which, if you don’t check them now, will make you lose several turns, so a dozen hours of issuing orders.
Take notes, so that, in a couple of days, when you start in earnest, you have a clearer idea of what you should do.
And I would say : don’t go back in time too often. You’ll learn better if you have to face the consequences, and, frankly, as the Allies, you’ll get way more of everything than you could lose, even if you lost everything you have on the map at start.