It depends on your level of English and how "simplified" the version you read was. I am not sure studying 19th century novels will necessarily improve your written English but it will add to your vocabulary and provide lots of examples of examples of elegant prose. You might try Pride and Prejudice by Austen and watch one of the many TV series/films of the novel as you read along. You could then write your observations of the story and characters and ask someone on Italki to correct your work. One of the best ways to improve your writing is to simply record what you do each day in the form of a diary.

Thank you Gillian, admittedly my listening english is worse, but it is still a very nice material for me.

https://librivox.org/jane-eyre-version-3-by-charlotte-bronte/ Jane Eyre is one of my favourite books, here is the audio if you might be interested. I do not know if you can access youtube but if you can then there are also several versions available.

Uhm, there are some very verbose dialogues that can be confusing, and it has some outdated terms that you'll have to read the notes about or look up, so it's a challenge, maybe read 50 pages to see how you do, and then decide if you want to go on based on the results.