Hi Stephen - well done for working your way through the great Jericho video courses. I remember when the voice lightbulb first came on for me.
The opening of a book is always tough to get right. Having read this before, it's more difficult to give feedback on, but I think the structure could still do with some work. At the moment, we see this dragon and assume that's going to be the scary driving force that launches him on this journey. But then Micah shrugs and just files it as another monster to be hunted, so the tension dissipates. Then we move through the world and see and learn some stuff, but I feel it lacks direction and pace.
Because Micah mentions the hunting, I wonder if this might be a better scenario to start with. You can use all the skills you've learnt from the courses to build a tense and exciting scene. Then maybe the more detailed backstory can be fed in during then next chapter/section.
I think you've got a great idea and world here. I'm just not convinced you're starting it in the right way.
I attach a copy of your file with thoughts that occurred as I read. Hope some of them are helpful.