Different writers work in different ways (you are going to hear the terms "plotter" and "pantsers" from multiple people -- plotters being those who plan first and pansters being those who just sit down and write).
However, you should be aware that there is an entirely separate activity/hobby/avocation called world building. The desire to build worlds and the desire to tell stories are two entirely different things. Some people, most notably Tolkien, spend years of happy world building and then decide to write stories. But that does not mean that world building is a necessary precursor to storytelling. It is a legitimate and enjoyable hobby in its own right. (In university I belonged to a club called the League of Semi-Real Nations. I wrote stories in mine, but other members did not.)
Stories, in the end, are moral. That is to say, they are about people making choices about values. You can build worlds to the end of time and never hit on a story about moral choices that interests you or is worth telling. And if you do have a story about moral choices that interests you and is worth telling, you only need do enough world building to create the stage on which that moral choice must be faced. And that may be no worldbuilding at all.
Of course, the moral choice that is the center of a story may come out of worldbuilding. You might start out with a worldbuilding idea such as, what if money grew on trees. Then you would ask, what would be the moral implications of a world in which money grows on trees? What moral problems would that create, what hard choices would that present to a character? And then you write a story about that character facing that choice.
But the point is that the process of storytelling begins when you have thought of a character who faces a choice of values. You then need to contrive a setting and a plot to bring them to the moment of decision. How much or how little world building you need to do that may then be much clearer to you.