BIT is NRA Basic Instructor Training. It's a course that all new NRA Instructors are required to take. It covers the roles and responsibilities of NRA Instructors, rules NRA Instructors are expected to follow, NRA teaching philosophies, filing your NRA class reports, and more.

Is it an NRA requirement to take the student course of a discipline before I take the Instructor course?

For Pistol, Rifle, Shotgun, Home Firearm Safety, Personal Protection In The Home, and Personal Protection Outside The Home, and Chief Range Safety Officer, it is required that the Basic (student) course of that discipline must be taken and passed before taking the instructor course of that discipline. When I schedule an instructor course, I generally schedule that student course immediately before that instructor course, and include the student course fee in the fee of the instructor course.