JULIE: Today many people use Facebook. And that is why there us cyber bullying.

CORRECT: Today, many people use Facebook. And that is why there is cyberbullying.

>>Be mindful of the correct spelling of words. 'cyberbullying' is written as one word. If the adverb is written at the beginning of a sentence, a comma is placed after it.

JULIE: They use facebook to bully. Such an unnice bullying, isn't it?

CORRECT: They use Facebook to bully. It is such an unkind/unnice bullying, isn't it?

>>Proper nouns begin with a capital letter. 'unnice' is not commonly used. The commonly used antonyms for nice is unkind and unpleasant.

JULIE: First one of them writes an unnice comment and others follow him or her. I thought about preventing them and it is them, I wrote under this

CORRECT: First, one of them writes an unkind comment and others follow him or her. I thought about preventing them and here are the ways to do it:

JULIE: Some people can't say about cyber bullying because they didn't youse the facebook with permission. Have a permission before you use it. Then, you can probably get some advice from your parents.

CORRECT: Some people can't say about cyberbullying because they don't use the Facebook with permission. Have a permission before you use it.Then, you can probably get some advice from your parents.

JULIE: Don't go to the site a lot. When you go to the site a lot, you get to think about cyber bullying other people. That is unnice to do, too. Write down the time you will youse the site, and make sure you keep that promise.

CORRECT: Don't go to a site a lot. When you go to a specific site a lot, you get to think about cyberbullying other people. That is unkind thing to do, too. Write down the time you will use the site and make sure you keep that promise.

>>Indefinite articles are used to refer to something for the first time. Be mindful of the correct spelling of a word. A comma is not placed before conjunction 'and'.

JULIE: If you have problem, you must not hide it. you have to tell that to somebody, but don't suffer the bully.

CORRECT: If you have some problems, you must not hide it. You have to tell that somebody so you won't suffer from bullies. 

JULIE: Those are the three most nice advice I read in books. Remember,  Don't be afraid to the bullys!

CORRECT: Those are the three nicest advice I read in books. Remember, don't be afraid of the bullies.

>>Be mindful of the correct form of adjectives. For the adjective 'nice', its superlative form is 'nicest', Be mindful of the correct preposition for the adjective 'afraid'. It is always followed by 'of'. The plural form of 'bully' is 'bullies'.