In a Class of His Own 1999 on netflix

Rich Donato is the high school janitor at an Oregon high school. He is looked up to by the kids who often seek his advice. There is only one problem: he doesn’t have a high school diploma. The school board tells him that he must get his GED in 30 days or he will lose his job. He tries taking the test on his own, but fails. His wife rallies the community to help Rich pass the test. Now that Rich has help from teachers and students, there is nothing he can’t do.