[Tyrant]

One thing to understand when learning this game is that it is a magic game with armies, not the other way around.

I second GP's suggestion that you start out with the Middle Age, but i would recommend a nation with more magic that Ulm, perhaps Marignon or Machaka. If you're having difficulty beating the AI a nation with strong province defense (PD) such as Marginon, Pythium or Ermor will be easier to win with. I'd also suggest skipping the Blood Magic nations such as Mictlan and Abysia until after you have gotten the hang of things, blood magic is weird and takes a little more effort than the conventional schools.

You might want to try Tien Chi next, they have a broad range of magic and that will give you a chance to mess around with lots of spells and summons.