[correction part II]

... believe in their first impressions because first impressions are often wrong. 
You need to specify your pronoun here, as in this sentence you are referring to 'people' and 'first impressions', and that pronoun could be referring to any of those two things.

In fact, these people are thoughtful and prefer to meet the other person, talk, drink a coffee or have a lunch with first, to be confident of their opinion about the other person. 
"In fact" seems like a better transition word in this sentence. We drink and lunch with people in English. When using the possessive third person in the plural form, we use 'their'. 

....normally these people like to talk in private, just with one person because he/she feels more comfortable this way. This kind of preference of interaction is not a bad characteristic... Thinking about that, a person that is calm, relaxed, and wants to talk and meet another people, can find a great person with good characteristics. This great person could even be a future friend..... people that think in different ways. Some people are reliable to trust in the first characteristics that they see. Although, Some people like to better understand and meet better the other person to, after that, think about the character of the person afterwards. It is easy to see that one can be more big-headed and do not judge the people just by appearance.... you might not have an appearance that others prefer, too.

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Some advice I would give you is to learn about cases in English, particularly when to use 'they', 'them', and 'their', and when to specify different pronouns. You either constantly rewrite the same subject, which makes your writing redundant, or not specify at all, which makes your writing confusing at times.

I didn't explain every correction, so let me know if you have questions!

[correction part I]

Prejudice
Since you are talking about something general, something that everyone may possess, for example, you do not need to add an article. 

....and do not try to talk to and understand other people... Some people prefer to be tolerant and, firstly, meet others and draw their own conclusions afterwards. 
In English, the correct expression is "talk to" someone. I've replaced some of you words with 'others', to make your sentence sound less redundant (you say 'other person' a lot, and that makes it a bit hard to follow). I've also added the word 'afterwards' at the end of your sentence, as opposed to leaving the word 'after' in the middle of the sentence, as it flows a bit better and also makes your writing easier to follow.

... who trust in their first impressions - that is, when one person knows another, [looks at them from head to toe and start to think why are those people like that. ]
Since you were not referring to a specific person, it is better to introduce the first time you use 'person' in this sentence as 'one person'. Singular nouns have verbs that are normally conjugated with an 's' at the end in the present tense, thus, 'one person knows'. I've also added a hyphen in the middle of your sentence, so that the sentence is not too long that it becomes a run-on sentence. I'm going to be honestly, I'm not sure what you meant to say between the brackets that I've put [], but I've corrected your grammar anyways.

...some people do not like tattoos and when they see a person with some tattoos, they think this person is not normal. Secondly, they think this person is not religious or do not believe in God. In particular, if the person has a piercing, now she/he is a terrible person for the society or is a bad influence. However, in many times someone that judges another person based only on the persons’ outer characteristics is wrong, because nobody has the power of prediction to describe other people without talking to, questioning, and being familiar with them.
Since you are generally referring to all tattoos, tattoos has to be plural (general preferences in English are normally in the plural form). When referring to a third person plural pronoun in the beginning of a phrase, the correct pronoun is 'they'. When we refer to society as a whole, there is no need to add 'the' in front of it. You have to say 'is wrong' as opposed to 'are wrong', because your subject in the sentence is a singular noun. Since you are describing the specific power of predicting, you have to add 'the' in front of 'power'. With regards to your last list, I've changed all your verbs to the present progressive so that there is a consistent subject-verb agreement.