If you are wanting to modify the windows on the menu screen, change their size/placement/content, I would look at
Scene_Menu
in the rmmz_scenes.js file and try to understand how it puts everything together. You'll notice most of those windows inside it are tailor-made for their specific functions and have a unique class name (
Window_Gold
, etc.). If you want to modify how one of those behaves look to those specific classes in the rmmz_windows.js file and read how it puts things together.
Usually you'll want to look at the
Window_Whatever
class code to change stuff that goes
inside the window (content, placement of content within).
If you want to put them in different spots or make them a different size or appear at different times or feed them different outside information, that is usually in the
Scene_Whatever
class portion of the code when the scene puts together all the pieces it usually creates an instance of the new windows and tells it where and how big to make it, etc.
Sometimes specifically with a few of the windows from the editor base code have the location and size variables defined inside the
Window_Whatever
class instead of the scene, you'll just have to check. Most custom windows will be written more extensible and not rigidly define those parameters internally, but its a case-by-case thing as I can't speak to how others write their code.
If you're writing your own custom Window class to hold special data (very common to want in custom functionality) I would look and seeif any existing
Window_Whatever
classes already do something very similar to what you want and then use it via inheritance when creating your new
Window_Whatever
in the
Window_NewWhatever.prototype = Object.create(Window_Parent.prototype);
section of the class definition of your new one. Doing this you can not have to "reinvent the wheel" and can overwrite any paticular sections inside it that don't behave as you would like already.
Some common ones are:
Window_Selectable
- has basic functions for interacting with contents
Window_Command
- has basic "choose from a list" functionality
Window_Base
- this is the most basic window you'll probably use, just has code to make an empty window
Window_StatusBase
- this has functionality for displaying certain content found in Main Menu screens like drawing icons and character images etc
Window_ItemList
- this has functionality for populating and interacting with lists of game items (actual items, skills, equipment, anything that you want to dynamically populate the list with stuff relevant to characters etc)
Again just look at what they do as is, then see how you can modify or insert something to do what you wish instead is gonna be the main way to do stuff with code in this program without headaches. I'm still learning myself, so some of what I say may be slightly inaccurate or maybe not the best practice, though I try to not recommend stuff I haven't messed with firsthand already.
There's lots of good info on these forums, and youtube has tons of good videos for learning about javascript. It's really not that bad, I'm not a pro coder by any stretch but was able to make some custom plugins fairly shortly after reading up on the forums, looking at other working code, and brushing up on some javascript basics. It is important to know that javascript does handle certain things slightly differently than most other programming languages like python or C# or Ruby or whatever, and learning those eccentricities will help you read the code soooo much easier.
Good luck!