If you were my child I would say: Most people are in your shoes. It’s maybe 10% of the population who knows what they want to do at age 18. Colleges know this too. So why do they ask these questions? Probably to find out how you think and what sort of vision you have for yourself. In other words, planning your life now and sticking to those details is not important. What is important is to see how your mind works in creating plans and in fitting into their school culture.
Taking the specific topics that you mentioned:
What matters to you?
An essay like this could be about something that seems small to others but is important to you personally (and then you make it more universal) or it could be about things that are important to everyone. An example of the latter could be global warming, for example, or the current election from one angle or another. Personally I find this harder to write about because it can easily get really generic. In general a good essay is one that deals with really specific imagery to you, rather than general info to everyone else. If you choose to write about a big issue like global warming be sure to discuss it in terms of something personal: the time the creek flash-flooded and swept away your house. A smaller issue could be out in the world, like (making this up) the handicapped ramp across the street from your house. People park across it all of the time. You could riff on this, why it’s important to you and what you did to fix the problem or not. Maybe you felt strongly that handicapped people need every ramp available and you took it upon yourself to lobby the city to paint a yellow line across the ramp to make it more visible. Or a small issue could be very personal: maybe you think sewing on one button on one particular sweater very carefully is important. You maybe could riff on how the button represents neatness. Neatness counts. Sewing things carefully: being careful is important to you for XYZ reasons. And then the kicker: your great-grandfather, he handcarved it out of whale bone when he was a sailor (or whatever) and scrimshawed it and it’s of vital importance. That essay takes something teensie and seemingly personal and makes it universal.
In all of your essays you should write it first. Write it long. Let your mind flow. After letting it rest, then cut it down to its essence and to the length you need. Use this http://theweek.com/articles/639004/how-better-writer-6-tips-from-master-linguist to help you decide what language to use. Also see Strunk and White’s book on style, which is great but the most important thing to remember from this is to choose images, simple words, and the fewer the better.
How do you see future school helping you with future career?
If you have a career in mind, great. If not, I think it’s perfectly okay to admit that. Most US schools do not require you to declare a major until sophomore year for a reason. We think exploring is basically okay, as a culture.
One way to handle this is perhaps by looking at what the school offers. Also, you know probably that you want to be a leader in your field, if I’m guessing, or at least successful person in whatever that field you choose. Success requires certain characteristics that you can learn at school. Maybe you can think of two or three examples. As for a major you can mention some possible ones, without being forced to stay with it. For example you think you may want to major in pre-columbian art and archeology or maybe econometrics, one or the other. Unclear at your young age. When you researched your college, you discovered several things that also attracted you to the school beyond the majors, like maybe the honor code, the museum on campus that houses precolumbian art that you’d like to work at and conduct research in, and the other aspects of the campus. Be sure to mention how you can contribute to the community by mentioning these things, in addition to what the college can do for you. I see myself contributing to X college by doing ABC and that ABC can guide me in the leadership and research skills that I may need.