Tomorrow

Tomorrow is [a week end] [in English, "weekend" means both Saturday and Sunday.  You could say "tomorrow is the weekend" or "tomorrow begins the weekend" or "tomorrow is the beginning of the weekend"] in France. I [have planed] [the present perfect would imply that your act of planning was in the past. since you have not gone to the lake yet, I would say "I plan to go to a lake" or "I am planning to go to a lake"] to go to a lake and read a book on the beach. [good]
I hope the weather will be fine because it's one of the last hot days of the summer season. [very good]
On monday kids are going again to school for a new year school. ["going again" is sort of French "aller deja".  I wouldn't use "again" in this sentence as the school year is new, but it could be reworded "On Monday the kids will go back to school again for a new school year] So it will be their last week end of their holidays. [good]

Now I'm going to cook a pie with tuna and tomato, which is a new recipe I have never cooked before.
I hope your Sunday will be fine too. [good]

Good work!

Seems fine. Maybe more clear to say "Some of the students did not want to do the assignment because it was not graded"

Introvert? Part one

If you wonder if you are an introvert or I if you are interested in how an introvert thinksworks, please watch some Ted Talks Conferences on that subject. There are only a few, but they are interesting.
The first one I watchedsaw wasis from Susan Cain. To summarize it very quickly: a third to a half of the population in the world is introverted. Introverts like and need to spend some time on their own, but not necessarily alone. Reading a book near the other members of your family could be an example of a social activity for introverts. Nobody is one hundred percent introverted or extrovertedextravert, every single person hasis a mix of both tendencies.
Everybody can contribute and will have to contribute to find solutions for all the huge problems our societies faceare facing, and for that reason everybody has to evolve in a context in which is favorable to think, and to create or to propose solutions. And for that, introverted people need more privacy, more autonomy, and sometimes more solitude. [But nowadays] ["nowadays" is informal, you could use "Currently" if you want to be more formal] our societies promote open space offices, and collaborating for everything, even in school, where a good student has to be an extrovertextravert.
InThe conclusion, : the world needs introverts and extrovertsextraverts to face challenges, so we all have to make sure that introverts can also find good conditions at school, at work, to be themselves, to think, to create and then after to share with everyone elseall the others their contributions.

Nice job

Just want to say "hello"

[Oh.] [This is a bit odd in English - maybe "By the way" is what you're looking for?] It's my first note in English. I'm a little bit nervous about it. But it's cool that I've decided to create write my first note.

Who am I?

My name is Vyacheslav. I live in the biggest city in Siberia (Russia). It's called Novosibirsk. There are more than 1 million people who live here. [You could also say "There are more than 1 million people living here."] I like this city but it's very cold here ["here" isn't necessary since you are describing "the city"] in the winter. Around 30 or 35 degrees below zero! Brrr... Very cold. But in the summer the city is nice good. The cCity has an active night life with parties, concerts and a lot of nice people. My city is very young. It's 120 age years old. Therefore, there aren't any [or "many" depending on what you mean] old buildings in my city., Bbut we have a beautiful theater building. I've attached a photo of this building.
That's it for today. In my next note I'm going to tell you about Academgorodok. It's small town near Novosibirsk. Actually I live there and I have some information I want to tell about it. See you later and have a good day!

Very good job.  Watch those articles!