Although all the information is intended for high school students, you still have to do all the things they ask you to. So that would mean sending in your SAT scores, completing the statements, getting in teacher recommendations, completing a candidate activity record, getting processed through DoDMERB (which, in itself, is sometimes difficult), completing and passing the Candidate Fitness Assessment, and whatever else they ask you to do. The only difference with you is because you have completed all 8 semesters of high school, you are to send all your high school transcripts in, as well as your college transcript when it becomes available.
In addition, I don't know what the deadlines for your congressional nominations are, but you really should start thinking about applying for a nomination. If the deadlines have passed, you can still seek a nomination from your ROTC Professor of Military Science, which is probably what you are going to do anyway; Vice President; or the Secretary of the Army, if you had parents who served or are currently serving in the military, or if you are a descendant of a Medal of Honor holder.
So although you're pretty late to the game, you can still get it started up. I suggest you complete your file as quickly as you can because that shows to admissions that you're interested.