"Harry Potter"

I started reading "Harry Potter" in English.

It's not normal to put a book title in quotation marks in text

Ther language is an easy language in this book.

So I can hope to finish it.

As the previous corrector said, this is probably best as a single sentence. You typically don't start sentences with "so" in English.

And I've reread it several times.

As the other corrector said, it's probably again best to link this to the previous sentence with a comma

I started to love reading after "having read Harry Potter", and I read a lot now.

It's clearer to me after inserting "after having read", I wasn't sure what "after Harry Potter" meant to begin with

This story returns me into my childhood, and makes me feel carelessness of thisfree about time.

Careless: negligent; it has negative connotations

Yes, childhood is a time full of hopes and anticipation ofor the future.

"Harry Potter"

I started reading "Harry Potter" in English.

I guess for langcorrect journals these quotation marks are fine, but, when writing, articles, essays, and short stories use quotation marks, while novel titles are italicized.

There is an easy language in this book.

So I can hope to finish it.

Connect to previous sentence with comma

And I reread it several times.

Connect to previous sentence

I started to love reading after "Harry Potter," and I read a lot now.

This story returns me in my childhood, m and takes me feel carelessness of this timeaway from my responsibilities.

I think I understand what you meant. You might also have wanted to say "makes me feel carefree"

Yes, childhood is a time fuill ofed with hopes and anticipation ofor the future.