There are two kinds of writers. Those who plan and outline every step and those who jump into the story feet first.
I'm reminded of that old question from Psych 101, where the professor said, "A kid is lost in the woods. I can give you beaters to comb the brush, or a helicoptor to try to spot him from the air, which would you choose?"
About 90 percent of the class chose the beaters. Those of us who took the arial view were told we were "right brain" or creative people, but lacked logic, because the woods might be too dense to see him from the air.
The "beaters" were told they were "left brain" people who had little creativity or imagination. They looked at life logically and took things one step at a time, but they lacked the ability to see the whole or the end result, rather than just the immediate next step.
Regardless of whether you are "right" or "left" you can be a great writer. There's no wrong way to do it.