You're introduced to the paradigm system on this Map, starting with a party of Lightning, Snow, and Vanille. You probably won't need a Sentinel very often, and do not yet have access to a Synergist or Saboteur, so experiment with how Ravagers and Commandos influence chaining, and keep a Medic available. The Crystarium becomes available after a cutscene early in the Map, allowing you to start leveling up your Characters. Early in the game you'll get plenty of CP to cover all the bases, so level up whatever Abilities or attributes seem most useful at the time for now. Don't miss the Pearlwing Staff for Vanille.