Hi there ^^ That´s a really cool topic. I´ve got some advice for people who whant to learn english faster and better : read and listen to a lot of texts, articles and if you can, watch all your films in english, with at first : french subtitles, then : english subtitles, and eventually : with no subtitles. They main thing to keep in mind if you want to progress in english is to remain in touch with the language itself, that is to say, to speak, read and listen to english words and/or sentences frequently.
The english wich is taught in highschools is an academic language, it will help you to write a good english, but in the end what is truly essential is to know how to speak well, how to pronounce well, and unfortunately, that´s what the french schoolar system keeps ignoring.