Ah yes, that is a little confusing at first. All action goes on (currently at least) behind the scenes, and you simply get a notification as to whether you won or not - as you've probably found out by now because I think we've had a battle?

Anyway, while the game is still in beta mode the battles are in fact shorter than the 2 hours - about 1 hour I think. What you need to do by 'preparing' is be active on Steemit until then, which is what counts and builds up your points. On your profile, the SPF (steempunkfactor) bar is what shows just how active you've been lately. (I think posting gives you the biggest boosts.)