Few question about blueprints inside blueprints and game stracture

Hi guys, I have a few questions hope you can guide me.

  1. is there a modern (2017-2019) book about unreal blueprints game structure?

  2. How to create a SaveGame blueprint object inside my GameInstance?

  3. how to create helper functions in a BlueprintFunctionLibrary?

  4. how to Spawn generic blueprints from my GameInstance? (with no 3d geometry that only manages and controls certain things)