Essentially, you'll want to create a Dispenser scene and an Arrow scene. The Dispenser will get a script which instantiates arrows.
The functions preload
, instance
and add_child
will definitely be required for this somewhere - preload the Arrow scene, and when one is thrown: Instance it, set parameters (such as velocity, I assume) and add it as a child of the Dispenser.
If you need help with a specific part of the implementation, let me know.