You are a very good story teller. You also have a lot of wisdom for someone your age at least in concern were imagination is concerned. You also have keen knowledge on your heritage which many sadly do not care for. You also do well in writing from a perspective of a child, something hard to do, and will get harder to do as you get older so learn and remember this story well.
Nonetheless,
“I have ever written and from the feedback I get will determine whether I should make more or stop trying.”
This is not the right attitude to take to critique or anything whether writing, or art, sport, or anything. Telling yourself you’ll stop when you get bad feedback will never get you anywhere in life. Bad feedback lets you fix something for the future. It’s your first story and you’ve taken the courage into sharing with strangers with many different backgrounds in relationship to writing. It doesn’t matter if it’s your first or you’re a millionth story there is always room for improvement.

As I have said you are a good story teller. Writing a story though is an additional art form on top of the story you are trying to tell. It would be the same if you were singing the story in song or making it into the comic. The form is as important as the story itself.

As you write a story there are three main things you need to thing about your audience (don’t know), the form (written story), and the story you want to tell.

The story told versus the story written are different things and reflect differently within the brains of the audience.
The story told involves audio, movement, eye contact, inflection, often more than one listener. It’s far easier to get people’s attention in this manner.

The story written is a one on one affair where the words must do all the work in the mind of the audience isolated from the author. Every word needs to count and defend the story where as they may not matter in the audio story with the same emphasis.

This is called showing in writing and one of the first obstacles developing writers need to think about. What do things look like and how do the audience seem them in their head? How do they feel with them and know them? You do have the skill for this, you just need to expand this to all five senses. Touch, smell, sight, taste, sound. Use them to your advantage.
What does Mylo look like. How does he feel when talking with Tin, when he gets the bear? How does the bear feel and think when it engages with the spirit? It is these things that entraps people in a story. Working them into your told stories can do a lot to, but in writing they are more essential. If there is just someone telling you something through written words it is hard to entrap. The words need to come alive and ensnare the audience and to last with the reader.

There is a catch here. That is your audience. Your telling style is quick and to the point and in it is its important wisdom. For the young and imaginative and the old and whimsical it does its job well. With a little fleshing out you could be a good children’s book writer. For it is here the story as story means best and most.

Form is also important. You need to keep in mind structure. Every new speaker or action create a new paragraph (indent). Blocks of text drowns your audience.

With that never give up on anything, especially story telling for it is one of the most potent and powerful things in this universe.

Also, a moral to the story only works well in that telling style with its weaknesses and limited audience. As a written story not for such an audience a moral can be seen as offensive and condescending to the audience as the author's voice circumvents the story. The moral should show through the story so the audience can see it clearly without being told. The relationship between audience, medium, and author is more tricky in writing then story telling. When people listen to a story they expect something and do not mind a lesson on top as that is what stories told often are for. In the written again it is a one on one thing with the audiences choice usually for an entertainment value, and an author overstepping the story can back fire which is why that kind of stuff is difficult stuff for a written story to make.

This story...was...nostalgic. For someone your age, your good. If only I had the motivation to work on my novel. But, I would like to read more of your stuff. Thanks for the good reading.