Making an interactive scene in Unity 3D

In this assignment, I tried to add interactive logic to a box and a horse. The problem I met is that the animation can't play correctly, and then I realized that we should choose "legacy" when we import the object into the scene. For the box, I used the object itself to be a trigger to play the animation and sound. (Sorry that I didn't find the sound for the box, so you will hear a sound of wolf when you approach the box and open it. lol.) For the horse, I used a flower as a specific trigger to activate the animation and the sound of the horse. It is a very interesting assignment, and I hope I can figure out how to use trigger to move the horse from one point to another.

Here is my work:

https://www.youtube.com/watch?v=x-jOmv8N1GM&feature=youtu.be

Extra Credit: