This is a fairly new form that the Army has implemented to try to consolidate a lot of the PCS information that used to take an entire folder into one source document. The information is pretty straight forward and your supervisor should be able to help you out with any abbreviations that might be stumping you (or you can Google it).
BUT your S1 is also failing you. Page 2 of this form MUST be filled out by your MPD (i.e. your S1) and you should NOT be getting the cold shoulder on this. I recommend using your NCO support chain because your S1 shop should have a Soldier specifically assigned to assist PCS/ETS/Chapter/Retirement transitions. As a matter of fact, the top of page 3 says "The Battalion S1 will answer all questions in Part II."
As one of my favorite former commanders once said, I don't expect you to do everything I do, I just expect you to do your job." Your S1 NCOIC needs someone to remind him/her of the duties and responsibilieshis inherent in their position.