Get position can grab and store the world position of a Game Object in the scene, so essentially you use Get Position to find out where something is located at in the world with coordinates on the X, Y and Z planes and then keep those coordinates either separately in 3 unique floats or all together in a vector3 variable. Vector3's can be thought of like basically just 3 floats grouped together.
Once you have a position in the world and have saved some coordinates you can use the Create Object action to bring something into the scene. It needs to know where to put it, so you just tell it to use those coordinates you saved. You can also specify a game object as the target spawn point, which is usually easier because you can just place and empty game object in the scene and target it for your spawns.
Make sense?
