Does the Army really need these documents in order for you to enlist?

Yes Jenny, I hope you will complete additional courses in formal English. That said, you will certainly need your High School Diploma and that is very easy to obtain at the office of your school. Now, if one of your parents' location is unknown, you simply report the facts you have stated here. You have not had any contact with your father in three years and you do not know where he is currently living. As a proxy to this, if you know the address of your grandmother or an uncle on your father's side, you may share this with the recruiter. Why do they need to know this? It is on record in order to notify the next of kin in the case you are killed in service. Remember, you are joining the army and the mission of the military is to fight wars. In any war, there are always deaths and the notification of the family. I cannot answer for your brother and his situation. Many jobs are available in all branches of service for college graduates, and many depend on the major you had in college and your grade point average. Some military jobs, if not most, have some kind of entrance exam to test your ability to preform at an acceptable level. Good luck and thanks for your service. Remember, the first six months will be the most difficult until you settle into a routine and assignment.