I am not a teacher, but I will be happy to correct some of the mistakes you have made in your essay. I think you did a great job - you have a lot of run-on sentences though, which should be split up. Do they use the term comma splice in your English class?
Today school is very important and I think it has become more important than it was in the past.
That's[This is] because , school and[an] education, that[which] every school should give to its students, are[is] fundamental to form[ing] [creating would be a better word choice here] well-educated and professional girls and boys. Many people decide to go to school and most of them also make the decision to keep on[continue] studying by attending university. This decision is born from the convinction[sp], according to which, who[that] gets[getting] a degree or attends[attending] school, has greater choices to get[increases one's chances of getting a good job. I think it could[this was] beright [correct is a better word choice] up to nearly fifity years ago. In Italy, the situation has changed and, what everyone can see, is that there are many graduated people[graduates], who have studied hard, who have also undertaken to attend school and then university, often attending specialistic[specialized] courses too [as well is a better word choice], and who do not manage to find any kind of job. [This is about 3 or 4 sentences worth of information - I would try to split it up] Really[Quite] often they do not want to get a good job, because they already know there is no good job[I would say "are no good jobs"] for them because of the European economic crisis, but they would like to get a normale[sp] job so that they can start a family, or give to their parents that[who] have paid so much money for their children's education, the satisfaction for all the economic efforts they have done. [split up into several sentences]
The problem is that school no longer assures the possibility[it assures the possibility, but not the certainty]
to find[of finding] a good job and it is a big mistake to go on [continue would be a better word choice] thinking and taking for granted that whoever has an education will be facilitated in finding a job. Of course, it is right to attend school to create well-educated people, or to let boys and girls socialize, but at the same time I think the convinction[sp] about a majior range of possibilities to get a good job must be knocked down because it is not concrete in our society any more![this sentence is very awkward - maybe "the conviction that school will provide a multitude of possibilities to get a good job must be knocked down because it is not longer a certainty in our society."]