This way people with same ideas can be united and create groups or movements.

To start with, cancel culture consists inof singling out people for immoral actions, such as racist, homophobic and sexist actions and then ostracizing them.

What happened next is thatAfter making those claims, she has been set apart.

In addition, cancel culture is a problem for freedom of speech as it consists in ostracizing someone for what hthey have claimed.

This problem is often shown in the educational system, because it prevents students and teachers from expressing themselves.

Indeed, in some universities in California, students can’t say what they want in order not to hurt some people, especially those from minorities.

Those rules whoich regulate people’s words are threatening freedom of speech as students are now scared to share some of their point of view.

Of course students, who have problematic points of view, despite what they have been told, such as racist, sexist and homophobic ones, generally know with whom they can’t say what they think.

On the one hand, many can’t express themselves as they’d wished they canould.

But on the other hand, many won’tuld be offended.

I think that although cancel culture was meant to regulate people’s words, it has gone too far and brought about many problems.

TrueWhile it is true that it is good and important not to offend the others, but whenif it hampers freedom of speech, it is no longer something good.

By freedom of speech I mean : Bbeing able to say what we are thinking while paying attention to others’ feelings, but if someone is offended, it is way better for the offender to apologize and talk with the offended to understand rather than ostracizing the offender.

This way people with same ideas can be united and create groups or movements.

It is now up toat a point where some denounce cancel culture for threatening freedom of speech.

To start with, cancel culture consists inof singling out people out for immoral actions, such as racist, homophobic and sexist actions and then ostracizing them.

She has been blamed for doing that.

This is accurate, but you would only really used "blame" if it's uncertain whether or not the person did the action (e.g. "the man was blamed for stealing the bike" - in this case, people are saying the man stole the bike, but we don't know for certain if he did or not). Because you said in the last sentence that J.K. Rowling definitely did do that, saying she was "blamed" for it is slightly odd. It might be better to say:
"She has been criticised for doing that" ("criticized" in American English).

What happened next is that she hwas been set apartostracised.

"Ostracize" in American English.

In addition, cancel culture is a problem for freedom of speech as it consists inof ostracizing someone for what he claimed.

It's increasingly common nowadays to use "they" instead of "he" in contexts like this.

So, many can’t backexpress their ideas, for cancel culture hampers their freedom of speech.

Indeed, in some universities in California students can’t say what they want in order not to hurt some people, especially those from minoritiey groups.

or "those who are minorities".

Thoese rules whoich regulate people’s words are threatening freedom of speech as students are now scared to share some of their points of view.

Of course, students, who have problematic points of view, despite what they have been told, have problematic points of view, such as racist, sexist and homophobic ones, generally know with who they can’t say what they think with.

or "with whom"

On the one hand, many can’t express themselves asin the way they’d wished they canould.

I think that although cancel culture was meant to regulate people’s wordspeech, it has gone too far and brought about many problems.

True, it is good and important not to offend the others, but when it hampers freedom of speech, it is no longer something good.

By freedom of speech I mean : Bbeing able to say what we are thinking while paying attention to others’ feelings, but if someone is offended, it is way better for the offender to apologize and talk with the offended to understand rather than ostracizing the offender.