Dear Magic Girl:
You seem to have a basic understanding of the writing task. You have expressed several thoughts that relate directly to the question of education and job-seeking.
Here are my suggestions:
Keep in mind that the task is:
1) to discuss whether the study of maths and foreign languages is more likely to help students get good jobs than the study of art and music;
2) to clearly state the degree to which you agree/disagree with the thesis statement; and
3) to give reasons for your opinion and to provide specific examples to support your reasons.
It would be good to make your opinion clear in your first paragraph. Do you agree or disagree?
Next, when you discuss what employers want, give very specific examples. You could name various kinds of jobs (engineering, retail, food service, medicine, etc., etc.) and state clearly how the study of maths and languages will help (or not) people looking for jobs in those fields.
Expand your discussion of our own experience with your musical talent. Be specific! What was your dream? How were you disappointed?
If you give very specific examples that support your point of view, the reader will be better able to understand your reasoning.
All best wishes,