Hey, Ester, I hope this helps!

Education - a Fundamental Instrument for Every Nation (Titles are capitalized)

Its (This should actually say "It's".  "Its" is a possessive adjective, while "it's" is a contraction meaning "it is") public knowledge that without education there is no future for a nation's to grow and develop growth and development. However, the Brazilian government does not seems to care about it. Despite its campaign saying they are it is prioritizing education, the population can't see any changes.

Even when a kid is getting poor grades on in school, the teacher can't reprobate reprimand ("Reprimand is the word you're looking for, but I encourage you to look up the word "reprobate", because it is a word!) him. The school has to have a certain number of students' (The apostrophe is needed here to make the word a possessive adjective instead of a plural noun) approval. Some mothers pleads plead (You need the plural verb here, which is "plead") for reprobate their children for their children to be reprimanded because they know their kids aren't learning well enough to pass. But, (No comma necessary here) the school says it can't do anything. They have to pass them to the next year.
In consequence Because of the non-reprobation this, kids are leaving the schools without understanding what they read and without knowing maths math and physics. These are the adolescents who enter college. If they can't don't even know how to interpret a text, how will they write an (We use the word "an" when the word after it is followed by a vowel.  The word "a" is used when the following word begins with a consonant.  If the following word starts with a consonant, but makes a vowel sound to begin, we use "an".  For example, the word "honest" starts with an "h" but sounds as if it starts with an "o", so we use the word "an") essay for graduation? And, moreover, how can these young people be prepared to enter the labor market? They are not.

Brazil has a lack of specialized workers because the schools can't don't prepare people whom does who do not have the most basic knoledges knowledge. This is one of the reasons why Brazil is receiving so many immigrants and so many older workers are still in the market. They can't retire. There is no one to substitute replace them.

So, how is the Brazilian government are pretending to increase and grow its economy, and with what workers? The youth are not prepared. The elders are getting retired ready to retire. The future is getting darker for Brazilian people...

I'm sorry to hear about this in your country.  America sometimes has the same problems.  Our standards for educating youth are not very high, and we are turning out people who cannot function in an educated world. 

I hope my corrections help you!  If you don't understand them, please message me!