well, first of all..English is a self-study language. If you wanna improve it you have to listen to native speakers and practice it. English isn't a complex language it just needs a strong determination. My humble advice to you is: (LISTEN TO ENGLISH SONGS WITHOUT LYRICS AND WATCH ENGLISH MOVIES WITHOUT SUBTITLES) try to understand the words. Then practice the language every single day, after that write a small paragraphs about different subjects.
It's very useful and I've tried it already. wish to you all the best :)