Oscar winner Aaron Sorkin is known for his prolific work, nuanced characters, and story telling that forms an impressive narrative. He has some really helpful tips and ideas for writing.
It is the core of writing and story telling. What does your character want? What does your character need?
Your characters can based on real people but they are not real.
The journey could be your story, it could be what your character goes through and how they use it to grow. Not all stories have happy endings.