SThe school year in Russia starts on September 1 and ends on May 31.

I want to describe a typical school day and how it was in my school in 2009.

ForTo entering in school, we,us pupils, had to proofve that we haved clean pair of shoes in our school bag.

We musthad to change our shoes firstly and then go to theour lessons.

must does not exist in the past tense - replace with "had to"

If someone forgot his clean shoes, heor her/their shoes, he or she/they had to go back home and take itget them.

Shoes - refer to as "them" because plural

The classes (lessons in Russia) started/would start at 8am AM.

Every class takesook 45 minsutes, and there iwas a 10-minutes break between every class.

At about 10:40, we had a 25-minutes break for lunch.

Nobody eats hise their food.

We all eate the food which was prepared in school.

During the school day, we mustcouldn't go away from the school building.

Usually, we had 6-7 classes per day, and then we canould go home.

If you are a pupil in ra Russian school, you are not allowed to be creatively.

Creative = adjective
Creatively = adverb

All you have to do is answer only as in student's using the textbooks and not argue with a teacher.

Student's books = textbooks
Your meaning here is unclear. Did you have to read out loud passages from the textbooks or answer written questions in them?

Now I understand that school in Russia was aslike being in prison for 10 years.

SThe school year in Russia starts on September 1 and ends on May 31.

I want to describe my typical school day how it was in my school in 2009.

FBefore entering inthe school, we, pupils, building, we had to proofve that we haved a clean pair of shoes in our school bag.

We musthad to change our shoes firstly and then go to the lessons.

If someone forgot his clean shoes, he had to go back home and take itget them.

The classes (lessons in Russia) started at 8am.

The (lessons in Russia) part could be omitted.

Everacy class takesook 45 minutes and there iwas a 10- minutes break between every class.

At about 10:40, we had a 25- minutes break for lunch.

We all eate food whichthat was prepared in school.

During the school day we mustn't go away fromweren't allowed to leave the school building.

Usually, we had 6-7 classes per day and then we canould go home.

As for the classes, they were really boring.

If you are a pupil in rRussian school, you are not allowed to be creatively.

All you haveare allowed to do is answer onexactly as in student's presented in the textbooks and not argue with a teacher.

Now I understand that school in Russia was aslike being in prison for 10 years.