How can i become a better football player?

im a football player on my high school team nd im a defensive lineman and offensive lineman(tackle). im a fsophmore and i want to know how i can be on the starting line and shine as a star on my team. i about 5'8 and weight 220. im chubby but im really strong so its not hard. im about normal speed and i've been workin on losing weight before football starts august 22nd so please help me out