The NJCAA has certain academic requirements you must meet in order to compete for any of their member schools. These requirements are different than both the NCAA and NAIA qualifications, and tend to be less complex at the NJCAA levels.
To meet the NJCAA academic requirements, you need to graduate from high school or receive your GED equivalent that can be approved by the NJCAA Eligibility Center. If you did not graduate from high school, you can become eligible by completing a term of college courses, 12 credits with a 1.75 GPA or higher.
In order to completely determine your eligibility at a certain school, you need to also meet admission requirements for the schools you plan on applying to. Colleges are responsible for determining your eligibility so in order for them to be able to do that, you need to apply and become admitted into their institution.