Question

how grades can affect your ability to achieve your
career goals. Include the subject areas that are most important to your career goals, and what
you might realistically do to improve your grades in those subjects.

Answer 1

... you ... you ... you ...

Only you can write this.

Answer 2

I think you're supposed to write a paragraph explaining how your school can affect your job and your future. And the part, "Include the subject areas that are most important to your career goals, and what you might realistically do to improve your grades in those subject" probably means choose subjects that you will use for your future job and what you'd do to increase your grade in them. For example, if you want to be a scientist and you have an F in science class, how would that affect your future and how would you change the grade?