I asked this question yesterday which was marked as too broad. One of the comment from @JBH stated this reason:
"How to build a world" questions are occasionally asked here. If the question is very specific they're left open. If the question is very broad they're closed. I'm afraid there are a thousand ways to do this, which is why classes in creative writing exist.
I strongly feel that my question is misunderstood. My question in no way is asking about all thousand permutation and possibilities of creating a new world by combining various gaming worlds. I am specifically asking about the possible roadmap, setting and starting direction in building my intended world, especially when cross-over worlds and ideas are overwhelmingly huge
That's why I also used "Worldbuilding-Process" tag which clearly scopes my question. The description in the tag states:
World building is a complex process that ranges from the enormity of the universe to the complex web of life in a particular location. Some created worlds are a minimum of information, while others are rich in their depth and detail. Both methods, creating what you need and creating everything, are world building and equally valid/useful.
Whatever drives you to create a world, maybe you need a setting for a book, a table top campaign, a movie, or perhaps a video game, World Building SE welcomes you.
Before asking that question, I had also read the guide to worldbuilding which is described in that same tag description.
The first question to ask is what kind of world do I want to create?
That I already have described in my question. I wanted to create a new world based on already pre-existing worlds.
Approaches to World Building - The top down method and the bottom up method.
I was/am confused in picking the approach, and that led me to ask this specific (not broad) single question. What approach can I take, How to sort and arrange the world properly I also received several helpful and great answers as well.
Where do I go from here? Jump in head first...or damn the torpedoes!
Unless you are starting from scratch for the sole purpose of creating a world odds are you have a story in mind. This is the best place to start because it helps define the world you want in some basic ways.
I also referred Help Center > Asking > What topics I can ask about here, which quotes this:
Worldbuilding Stack Exchange is a site for developers, designers, writers and artists to get help creating imaginary worlds. This includes geography, culture and creatures for the world. Questions on this site should be about building settings (for which I asked question about how to build one) and the reasons around why they are the way they are
Lastly, a minor point about the comment quoted in the question "..which is why classes in creative writing exist." - I hope this was in no way intended as a provoke though it sounds little like that.
If the questions asking about getting started with a particular setting, approach or direction of starting with world building are Off topic on this site, then I seriously have misunderstood something - or either my question is wrongly put on hold.
I request anyone to clarify on this please.