Hey high school self. I know you've just graduated and want to take a year off to know what you want to do, but don't let yourself stagnate. You don't have to settle for a job you hate because you think things will turn out better on their own. You've got to get out there and achieve your goals yourself. Simply going to college won't bring success, and you need to realize this. Don't depend on the institution to give you achievement. Depend on yourself for it. When you embark on whatever course of study you choose - and it could very well be something different than you think you want right now, as your future self can attest - give it your all, know what the end goal is, and always be reaching out beyond the borders of the college towards opportunities in the real world. It's easy to work hard all the time for that A+, but remember to work hard for the skills that A+ will bring you, that will carry you beyond school and into a rewarding and fruitful career.
I would first tell myself to save up for Nashua Community College specifically. I had attended another college previously in Ohio and ran out of money in 3 months and could not find a job. Second I would tell myself to start with a basic math class so that I would not have such a hard time in my other math classes.