So first I have to ask a university and then to get the VISA?You have this all mixed up. A green card is issued for permanent residents; it is distinct from a visa. One option is to win one via the green card lottery, but this is but one very limited option; there are more common ones. All this is moot in your instance: A green card is not needed to study in the US. There are different categories of visas. To study at a university in the US, you need a student visa. If you are accepted for admission to a university in the US, the university admissions department will assist you with filing an application for a student visa. The US so far has been very welcoming of foreign students.
To be admitted I need to do interviews ?
Cause in Italy is different, 90% of university don't have any test and accept all the students, this is because very few people go to the university.
It's not easy, you know, italian is not my primary language, I speak three languages, and German is very difficult because is not a Latin language, it would be more easy to learn spanish, or french, but I would need at least 4 months to learn German and I don't have time because I go to school, and as you may not italian school is very hard.If Germany offers you the opportunities you want, then take an intensive course in German. That is under your control, and limited only by yourself.
I would like to, but there aren't many italian university well-know, I suppose, I would like to go to a USA university because are well-know and are in english, but it's not easy I suppose, also because I don't know how hard is to apply.Then apply for a brand-name school and see if you get in. In general, making choices leads to limitations of some sort.
You can think at the fact that in Italy we don't know what means " apply" to university, because we don't do, and also my teachers of high school don't know what this means, they also told me " we lived in another situation with no globalization".