My project for course: Stylized Vector Illustration with Color and Character

The course helps me learn how to use reference images to turn them into stylized shapes and how to organize each element to make it look nicer.  I'm still not sure about the layout was arranged. And a lot of struggle to combine these colors. I tried not to imitate teacher's color palette, I found another to adjust hue and brightness, but it still seems a bit chaotic here.
Thanks your course a lot.