Default Battle Setting
BP_AFT_DefaultGameConfig
This is where you can configure the default selected characters for testing without going through the menus.
Locate: SomndusStudio/AFT/System/BP_AFT_DefaultGameConfig
If you want to detail the selection for a team, here's an example:
For opponent/cpu
Generally, CPUs are on TeamIndex: 1 (the second team)
Open Battle Stage
Then you can open : SomndusStudio/AFT/Mode/Battle/Map_AFT_BattleStage
The stage loads an instance of the selected stage.
Default Game Mode
Since the default installation, Training Mode is activated. So the map should play as Training Mode.