welcome to the forums and a epic game,
for me, none of the above is needed if you have just started imo
learn as you play, start off on the smaller battles and don't go onto a full blown campaign until you have won and done so on a few levels of difficulty
like everything when you start, let the AI do anything it can do, so air for one and do the rest your self, so in all facts its a counter moving game like any other, then and only then progress to the manual and the deeper stuff, so for me you pick the lowest level of difficulty and turn on all the AI support and turn FOW off and the quickest smallest battle and play and enjoy the game while you learn it.
play over and over again and each new game turn the difficulty up until you loose a given battle, still not going onto the full campaigns etc mind you, just all the smaller ones for now, and once beaten, read until you can win on the one you lost on, this way you learn and have fun and carry on playing while you learn, as some can be put off if they loose to often and go to deep too quickly,
once you have the weeks and month in, you will finally get to a level where you're then happy with, try a campaign or 2 and see how it goes, once you have done them all and are still enjoying it and winning, play online, as by now a year or so will have gone by and you will know more, or unless like me, stays at a given point and doesn't wish to know how many tins and cans are needed to invade a given point so stays at a given level as still loves and plays it most weeks quite happily and still doesn't know nato signs :)