How do I create an instance of a blueprint actor from within the Level blueprint?

You’re looking for the “SpawnActor” node. Select your box blueprint for the class.

I have a box blueprint. I would like the level to randomly place boxes around the level.
How do I create multiple instances of the box.

Event BeginPlay-> For loop-> Generate RandomVertex-> ???

Whats the command to create the object?

You need to create InstancedStaticMeshComponents and then add them using Add Instance. Do it in the construction script side of the blueprint.

Epic Construction Script tutorial: