Make a habit of reading regularly. Read as many English books, newspapers and magazines as you can get your hands on. You need to read materials from many different topics and disciplines. The reason is so simple: because every topic or discipline has its own terminologies. Don't try to read "the classics" straight away. Save them for later, start with contemporary short stories.
In British English, for example, there is a series of books called the Oxford Bookworms Library. These come in seven levels. To read a 'starter' book you need to know around 250 words of English vocabulary.