Start with basic grammar , learn English grammar by BBC is a wonderful app , read atleast two editorial daily from the Hindu , nytimes or from any magazine on various topics , make habit of noting down the words you encounter for first time and try to find out complete details of it , add atleast 5 new words daily in your list and go through your list on weekly basis , my word list is a wonderful app for making your custom words list additionally it provides you lots of details of the work like antonyms, synonyms etc with lots of examples also you can add your custom sentence too.
Try to solve mock tests on va and rc freely available on internet but make sure to follow quality resources.
Understanding the paragraph is much more important than just reading it so try to focus on getting the idea behind the passage.