It's your first campaign so you're obviously playing as Rome. Here's what you do:

*Disband one unit of cavalry.
*Disband one unit of Triarii.
*Disband one unit or Rorari and Accensi.
*Set taxes to as high as possible without the face turning yellow.
*Merge the two armies EB gave you to start with.
*Pick a general to lead them, replace him in the city with the unit of Leves you didn't disband.
*Conquer Taras and Rhegion with army.
*Watch the money flow into your treasury.
*Build your buildings, conquer more cities.

And a good time was had by all.