I would like to make a script that has sort of a scene prefab that is created for a new world, is there any way to do this in unity? Also, do the scenes in unity save changes you have made to them in the built version of your game? (like instantiated objects)
For this, I use an empty scene as a template and build the content based on what need ( can be predefined, can be hardcoded, can be several small scenes I additively load anyway you want to store the definition of the content you need to show basically).
Check this question and answer, it explains one way to achieve what you want to achieve AND as a bonus be sure to have the garbage collector working on iOS.