Decent freshman year but I need help with gpa

Hello I am a sophmore in highschool and I have struggled with my freshman year and ended up with an 84 average that year. My Freshman year biology teacher was teaching out of an AP book in which he did not give us any guide to tests so I basically guessed the tests he gave us. But in sophmore year I switched schools and I am doing a lot better this year. I increased my gpa up to a 88 and I just started the 3rd quarter. do I have any good chances getting to any good schools… I am moving up to ap and honors classes next year which is good. My goal is to major in finance and to go to a college in New York, where I currently live. How could I improve my gpa??? help!!