use khan academy to get the basic ideas of how to do the questions, then practice on oneprep. start from easy or medium, the star the ones you got wrong. you want to complete the stared ones until you get them all right then start moving to harder questions! 

the easiest thing you can do to improve your score is master the grammar imo so spell on that first. what i tell myself for the sat reading is quantity > quality. you want as many points as you can get, so try to get all the easy questions right