honestly the fastest way to learn is just watch replays...wc3 is a very systematic game, especially with hu/orc. After watching 3-5 replays you will see patterns that include strong build orders, base builds, unit combos and play styles. You will notice players constantly moving their units around the map, this isn't sc2 - you don't really sit in your base ever. The reason you can move around the map is because of the teleport scroll that comes with your first hero. Use that wisely to defend your base or save your hero before it dies.
Beating AI is simple, just kill neutral units until your archmage is level 3 (level 2 water elemental/level 1 aura) then push the opponents base. The fastest way to win a fight is kill the other players heroes...it's basically auto gg.
maybe ill reinstall and come play so you can watch me pwn~