It is not clear, for which class the essay is needed..
There are many uses of going to school. We can find as many disadvantages of not going to school. We go to school without actually knowing explicitly why we are going to school.
We live in a society having a culture, purpose and history. Every person does some thing to earn money to live comfortably by doing some job. In order to do a job, we need some skills. We need to learn skills like accounting, engineering, testing, flying planes, handling machines in workshops, designing machines, electronics, computer programming etc. To perform any job properly we need basic knowledge in various subjects like mathematics, science, history, geography, civics, accounting, economics, computers etc. School is the institution where children are taught the basic knowledge.
Man lives in a society. So he needs to interact with other people nicely. In modern society we communicate using national and international languages. We need to develop our wisdom and to nurture our intelligence, to be able to solve our problems by the use of the knowledge gained. All these happen in the interiors of the temple like school.
School teaches us discipline, independence, culture, sharing, sportsmanship, obedience, ethics, morals, hard work, leadership etc. These are qualities required for one to be a good human being. One may learn cultural and performing arts too. Also, one identifies oneself, one's own skills, one's future by the end of schooling.
School is a place where we learn hygiene, nutrition, health, cleanliness, superstitions, good and bad practices, logical analysis, and objectivity. We use that knowledge to take care of ourselves.
It is the right and duty of all children to go to school. School is a place to enjoy life while learning. We learn a lot of what our elders have done before us. Learning all that enables us to progress in future.