You have a very good grasp of written English. I have just a few suggestions for a more natural flow. "I don't have any plans for my future job."- We would say,"I haven't decided what kind of job/career I'd like to have, yet." "Of course, I will go to the University soon so I have to choose my future profession as soon as possible."- Instead "But since I will be going to school/college soon, I should choose as soon as possible." "Anyway, my future job should be connected with Mathematics, Chemistry and Biology because these subjects are my favorite and I know them very well."- You don't need "anyway" and we would more naturally say, "I'd like to do something in Mathematics, Chemistry and Biology because these are my favorite subjects and I'm really good at them." " Also I think my future job will be connected with computers because I'm really interested in programming and computer games."- Try: "I'd also like to work with computers because I'm really interested in programming and computer games." "Speaking about background like, personal skills and qualities, I can't say which of themy I will need for my future job. It depends on what I will be."- Two things for these sentences: 1) To keep the nature of it, say- "In reference to my background, like personal skills and character traits, I don't know which of them I will need; it depends on what I decide to do." 2)This sounds really awkward with the rest of your story because you have a very good idea of what you'd like to do, and so the idea that you don't know what character traits or skills you possess that would lend to your success is puzzling. I would imagine you are organized, detail oriented, creative, focused, etc. Choose things like these because they naturally go with the jobs you mentioned and then your story will continue to feel authentic.