In the Modes panel, select the Place mode.
Select the Basic tab and drag a Player Start Actor into the viewport. This will act as the starting location for the player, so place it where you want the player to begin the level from.
In the Content Browser, select the Content folder and search for EnemyStart. Drag a few instances of this Blueprint into the viewport. These act as locations to spawn the robots from. Place them wehre you want the robot waves to eminate from.
In the Content Browser, select the C++ Classes folder and search for OdinAIWaveManager. Drag an instance of this Actor into the viewport. The location is not important as its job is just to act as a controller for spawning the robots, but you should place it somewhere easy to find and select.
You now have all the Actors necessary to create a wave of attacking robots. There are some properties to set and connections to make before they will do anything, so let's do that now!