OK great! Army, AF and Navy all run their scholarship applications and interviews differently. What may apply to AF and Navy may not apply to Army.
The AROTC scholarship requires an interview. This interview may take place a College battalion that is considering offering you a scholarship or the Battalion nearest to your home. Hopefully, you are/will apply to the school where you are interviewing.
The interview is generally conducted by the Professor of Military Science - usually a Lt Col. At my daughter's interview the Prof. of Military Science, enrollment officer (a Captain) the Battalion NCO and several cadets were there.
Interviewing early is a bonus - this puts you in a position of an early offer. Remember though you still need to be accepted to the college.
AROTC is looking for scholars, leaders and athletes. They want to be sure you have the ability to be accepted to the school, have leadership potential and the ability to pass the APFT. Varsity athletics in high school is a plus as is the desire or willingness to participate in athletics in college - either competitive or intramurals.
They will ask you why you chose Army ROTC, your feelings about your Army commitment, your activities in and out of school, including any jobs you held.
My daughter prepared a resume detailing all of her activities and accomplishments - she passed out copies and kept one for herself and it really helped her to remember what she wanted them to know.
At her interview they also had her bring PT clothes and ran her through the APFT - it was just to see how well she did. It didn't count.
She also got to talk with some cadets and got a tour of the school.
First offers don't officially go out until the fall. Some units don't make any offers until late winter or spring - when they know if the student has been accepted. Other battalions use a sort of rolling admissions and the early bird gets the worm - esp if you are highly qualified.
All other interview recommendations apply - do your homework, check out the website, learn names. Shake hands and look at your interviewer when answering questions. Relax. In this interview they are selling their school and battalion as much as you are selling yourself to them.
Offers of a scholarship are at the Battalion level. They in effect are competing against each other. There are 4 offer dates - I forget exactly but roughly Nov, Feb, April and May. If you are offered a scholarship early you may accept it and then decline it later if another school makes an offer. You may accept only ONE offer per offer date.
One more thing - it's not elusive - it's fun! My daughter had a blast at her interview.
Good Luck!