Part 2; Please read Part 1 first.

2/ I may be missing something but I can't see why you added the "or not" there. It would make sense if you were saying "for me that determines whether it is normal or not", but what you seem to be saying is that predictable behaviour is normal; "or not" isn't needed.

I'm going to have to rewrite that one since I can't break it apart that easily.

Finally, we assign someone who doesn't share social norms and has unpredictable behaviour to the category of abnormal people.

1/ The first problem is that the people themselves are not a category, but rather they fall into a category. An alternative way of saying this would be:

"Abnormal" is a category into which we assign someone...

But again, the people are not the actual category, the people are in the category.

2/ I would use "has" rather than "had" here. "Had" seems to imply that they once had unpredictable behaviour, but don't any longer.

3/ Again, if you use "an unpredictable behaviour" it raises the question of which specific action is unpredictable. I would therefore drop the "an" and just say "unpredictable behaviour". You could of course also say "an unpredictable pattern of behaviour".

So, is it good or bad to be normal?
I’m not sure and I think that psychologists are able to answer better than me, but if to be normal means to stay on the rails, accepts accepting rules that we don’t share and renouncing the ability to see with 360 degree ... not, I prefer to be abnormal, especially because… normality and abnormality don’t exist.

1/ When talking about a behaviour you would normally use the form "X means to Y", or alternatively use the gerund form; "X means staying on the rails". Similarly you could say "to accept" or "accepting", but it wouldn't be "accepts"; that is something that a third person does. "John accepts that he will have to work harder at school". In this case I used the gerund; accepting.

2/ I see what you are saying with "share" but "believe in" might more clearly express the idea here. Using "share" is not wrong and is clear enough, though.

3/ 360 degrees is not something that you see with, but rather what you can see if you look at all sides of an issue. Accordingly you would be talking about an ability to see 360 degrees.

I'm not sure why you haven't received any corrections yet; this one seems clear enough and easy to correct. In any case, with Italki's character limits this will be part 1 of the correction with the rest to follow.

What's Normal?

In English, you capitalise most words in a title.

The expression "What does qualcosa mean..." is roughly equivalent to "Che cosa significa...", but in English you need two verbs; "mean" (which is roughly the same as "significa" and the auxiliary verb "do" (in this case "does").

I would start with the meaning of this word.
“Normal” means “conforming to the standard, common, regular”. But what’s the standard? How can we differentiate normal people and abnormal people?

1/ First of all, way to go with the apostrophe in the word "what's". The use of apostrophes often confuses people from non-English backgrounds but you got it exactly right. 2/ You can't say "How can verb". You need to have a noun or pronoun as a subject of the sentence; "How can {subject noun} {verb}". In this case it would be "How can we" (we being the noun), but you could also say "How can one" (which is rather formal English) or "How can you", though in that case "You" would not be the specific reader but rather the set of all third persons in the world.

Everyone agrees with the concept that normality doesn’t have a specific content, and that it depends on social factors, cultural factors and historical context.

1/ Because "Everyone" is a collective noun (like "la gente") it needs to use the singular form of words; "agrees" rather than "agree", in the same way as "John agrees" vs "John and Maria agree".

2/ I see what you're saying here but I'm not sure I'd use "content" like that; it's a little vague. I would probably say "doesn't consist of a specific set of behaviours". It's longer, but it's clearer. In general it's better to write concisely but don't be afraid of using extra words if you need them.

However, this word also means “norm” so we can say that a normal behavior is anything expected. Consequently, when a subject had a predictable behavior, for me it’s normal or not.

1/It's not actually wrong to say "a behaviour" in reference to one specific action. For example, paying for groceries after you have put them in the basket in a supermarket is "a" normal behaviour". However even then it could be argued that this one action consists of many sub-actions; giving the goods to the cashier for scanning, taking money out of your pocket, giving it to the cashier, putting the items into a carry bag and so on. Accordingly it would be more common to use "behaviour" more as a collective noun; that is, something that represents a collection of individual actions. Therefore it is better to say "behaviour" rather than "a behaviour" since you no longer need to break it down and say which specific action you're talking about. (Note that I use the international English spelling for "behaviour"; yours is US English which is not wrong, but different.)

To be continued...