You should start by explaining what you actually think the above professions are and what they mean to you. You're only 15 so i wouldn't focus on 'choosing what you wan't to be' asmuch as trying to find out which field of study you love!
Take the time to research the prerequisites for the programs you think you might apply for (school guidance councillor) as well...
Regardless of which profession you decide to follow, try to include the following in your course selection (all are requisite to those 4 things you have listed except biology, but biology is fun): upper level math, physics, biology and chemistry. Economics, and law could help too.