I'm a bit late on this, but I would say avoid Quick Battles as they usually aren't that challenging. The AI selection of units and their control is not great. If you're playing single player, play those battles that say 'play as Axis against AI' (or whatever floats your boat) or choose a campaign that you like if the one you mentioned is not working for you.
But the best way to play is against another human, PBEM in my case. You might (okay, will) get your butt kicked every now and then, but it's a great learning experience and you tend to make some good friends.