how can i educationally wise increase my chances in getting in the NFL

Ken's advice is excellent about having a backup plan, and I would very strongly encourage you to develop that backup plan. But to answer your question, the best way to increase your chances of an NFL career in the classroom is to work very hard and do well academically, so that you have a choice of colleges. You wouldn't want to do all the work of getting recruited in your sport, only to find out that your grades and high school coursework aren't good enough to get you admitted to that school. If your grades are good, you can choose between the schools that recruit you to pick the best fit for you - academically as well as athletically.

Conveniently, this strategy will help you both with your Plan A (football) and whatever your Plan B will be. Good luck!