So other people have already told you about different methods to write and have assured you that not having it "together" when you start the story or even halfway through is not unusual for a writer. This is all pretty normal stuff in the hell that is drafting. So I'm not going to add to all that sage advice
Instead, I'm going to point you in a couple of directions that helped me with my character motivations and how knowing those motivations helped me structure the plot.
Robin LaFevers wrote several blog posts on her process of determining and planning out her characters' motivations.
I also like some of the exercises in the snowflake method.
Finally, I read Save the Cat! It's pretty formulaic, but he spends some time talking about character motivations at the scene level—that every character enters not just the story but even each scene with a goal and motivation and that the scene should drive toward that goal, answering it in some way. It helped me connect some of my scenes to my characters where the story was, otherwise, falling flat.
rquinlivan said:My characters' motivations make no sense and I don't really know where any of this is going.
Instead, I'm going to point you in a couple of directions that helped me with my character motivations and how knowing those motivations helped me structure the plot.
Robin LaFevers wrote several blog posts on her process of determining and planning out her characters' motivations.
I also like some of the exercises in the snowflake method.
Finally, I read Save the Cat! It's pretty formulaic, but he spends some time talking about character motivations at the scene level—that every character enters not just the story but even each scene with a goal and motivation and that the scene should drive toward that goal, answering it in some way. It helped me connect some of my scenes to my characters where the story was, otherwise, falling flat.