To improve English means to develop skills of English language i.e. reading, listening, speaking and writing. You are advised to read newspaper, magazines, stories, etc watch TV programs & videos in English and try to comprehend the interaction.
Discuss with your friends about events, people, likes and dislikes and ambitions in English.
Try to write e mails, letters to your friends, your daily diary and put down your own ideas in black and white. And read short stories and novels by famous children writers. Hope you’d improve you language skills in English.