Shinobi Student is the generic term for the students who want to be shinobi, whether good or evil. There’s no age restriction for those who wish to be students. Despite only being students, they are also officially considered to be shinobi and will more or less receive the same treatment as graduate shinobi.
When becoming an official shinobi student all are assigned the ninja rank of Genin. Shinobi students can then increase their ninja rank in school by undergoing a promotion exams to test their skills.
The curriculum varies between Shinobi Schools, but in general shinobi students spend their time learning the basics of being a shinobi such as hand-to-hand combat, utilizing various ninja tools, how to use Ninja Arts, and so on. Students go through a variety of exams and tests to improve upon their skills in various areas.
After three years of studying and training they are given the opportunity to graduate and enter the professional shinobi world. All shinobi schools have differing graduation tests. It is possible to pass the graduation exam and still remain a student of the academy by choice, as seen by Daidōji who refused to leave Hanzō Academy despite having passed her graduation exam.