Win condition: Rout the enemy
This map is meant to give you time to get used to Celica's army and units. Notably, the terrors here will respawn once you return to the map. Feel free to return here to grind once or twice more if you're lookin for an edge before proceeding. My advice: get every unit at least to level 2. In doing so, some will reach level 3.
To clear the map, target the terrors from ranged distance, never leaving your units too open to attack from too many terrors at once. All of your units are level 1, but be careful with Genny, as it would be a shame to lose your Cleric so early. Defeat all of the terrors to complete the map.