This is a great lesson for every poster and lurker, don't go down this path for the scholarship or the dream college only offers this branch for ROTC. JMPO I am assuming this is why you are in AROTC now and not NROTC, that or a recruiter fed you line of bunk saying it would be easy to go into the Navy as an AROTC commissioned officer, now sign on the dotted line.
Placing that aside and going with you were unsure of which career path, you still will be facing the fact that all 3 of these career fields are insanely competitive. It is great to have career goals and aspirations, but it is something that is secondary from the military's perspective. You serve at their pleasure. When you enter this realm (ROTC), you need to prepare yourself for not ever obtaining that goal, and being happy to serve in whatever and wherever the branch determines is the best needs for the military. Getting that dream career field is a perk, not a guarantee when you enter.
Look at this even deeper. Let's assume, that you can transfer into the Navy, but there are no helo or submarine billets, instead they place you in Public Affairs. Will you now want to switch back to the Army, hoping to get that flying or infantry slot?
I am not trying to be antagonistic, instead realistic regarding AD military life. Not everyone is in their 1st or 2nd pick career field and many are at installations that are not the hotspots people shout send me there! They enjoy their life because they are happy with their branch.
Long ago I heard this statement, you can't hate 8 hrs of your day because you hate what you are doing, and 8 hrs of your day because you hate where you live due to that job (remaining 8 hrs are sleep) and expect to be happy. You need to choose 1 because more than likely if you love the job, you will like where you live. If you love where you live, than you will like your job.
Problem for the military is loving where you live is an added bonus, it is not a guarantee, thus loving your job will be more important.