If you dont have good micro and you wanna win with humans.. than just get more stuff than your opponent has. Or else you cant win, because your micro. So at the start of the game, early expand... Other than that, just have the right combo of units to counter what he goes.. you weren't that specific.
micro is the control of your units in battle nad creeping.. macro is control of your buildings. microing.. is like if unit is being targeted u move back then heal and he comes back and useing your heros spells ect... undead strategys..... all depends what other person gets, it common sense.. if they go air get Gargs., but always have some ghouls so you cna get there heros good.