Need some feedbacks on my writing

Hi,

I am applying to a credential program and have to answer 2 questions on the application. I need some feedbacks and correction for my responses. Can you guys please help me out. Thanks !

1. How do your background and/or experience inform your decision to pursue a license that authorizes one to work with socially, culturally, and economically diverse groups of children in the state of California?

I didn’t go through the usual route of majoring in education, although teaching was always my calling. I started college majoring in Mathematics and Education, but I changed my major to Pre-Med after my softmore year because I wanted to be in the same field with my group of close friends and my ex-girlfriend at the time. Most of us believed that teachers do not make a good living, whereas doctors or dentists are almost guarantee to have a prosperous live. I never like biological science but I did manage to get in dental school. However, I quitted dental school after two years and went to work in the biology field. But, I wasn’t happy with what I was doing, so I quitted and opened my own business in photography. I was not in love with my business either, but it made good money and because I had put so much money invested in it so I had to hang on. I had two photography shops for over six years before I closed them down because the new digital photography technology came out and killed the whole traditional film photography industry. But even when I was doing well with my photography business, I still tried to find time to teach on the side, because that was what made me happy. I still teach Food Safety and Environmental Health on the weekends and I have been doing that for more than 12 years already. It's hard to describe why I want to be a teacher, but my heart tells me that teaching is what I am meant to do. I had taught and tutored since I was still in high school, and it was always my comfort zone, a job I could always fall back on to make some extra cash.
I came to this country as a refugee and I am always been thankful for all the things and opportunities that this country had given me. It is my obligation to do something to repay what I have owed. Helping children from different socially, economically, and cultural background to learn and grow is probably the best way to make a contribution to society. Becoming a teacher and teach children come from different socially, economically, and cultural background is probably one of the best way to do it. Although the teaching profession doesn’t get rewarded in term of money, but to me it is a noble profession because teachers are helping to grow the minds of the next generation. It would be heart fulfilling when you can make a difference in one’s life, and to me it is far more valuable than reward of recognition or money.
2. Why do you want to work with groups of children between the ages of 5-11 or adolescents between the ages of 12-17?

I prefer to work with group of adolescents because most of my teaching and tutoring experiences involved around junior high, high school and college students. I always feel comfortable being around them. Especially, I love teaching high school because the kids are capable of conversation and critical thinking. It is very challenging to work with teenagers but it’s self-rewarding to see them success. High school teenagers are at this intersection of teenage exploration and adult expectation. They need someone to lead them in the right direction, and help them maneuver their way through the messy time. They need encouragement and an inspiration during a time of frustration or confusion. I enjoy helping them develop their critical thinking and nurture their minds with many perspectives in hope they can form some aspect of independent, informed opinion that help serve them for a lifetime. I have been through the ups and downs in life; I was lost, confused, and made mistakes with my career direction so I want to use my life experiences to guide the future generation on the right track.