A couple of things. First, BGOs are typically assigned to particular schools, at least in our area. In less populous parts of the country, they may cover a bunch of schools in a certain geographical area . The fact is there is typically one BGO assigned to any particular school and BGOs know the school(s) they cover. Area Coordinators, OTOH, are assigned regionally -- typically one to a state for less populous states and more than one for populous states. They don't usually work with candidates; rather, they coordinate and manage the BGOs in their region. If your school career counselor does not know the BGO that covers your school, contact your Area Coordinator (name available on the usna.edu website). He/she will put you in touch with the right person. Note that the other SAs may take a different approach to assigning their equivalent of BGOs.
Second, enlisting in the military is a terrific way to serve. It is NOT a terrific way to enter USNA. It can be done but is a long shot and no one should enlist expecting/anticipating that they will be able to attend USNA. This advice may not apply to enlistees from the Army and Air Force -- I simply don't know. It is SOMEWHAT easier (cannot emphasize that word enough) to become an officer from the enlisted ranks, but again, not an easy path. It can be done and is done, but isn't the normal route.
In order to get into NROTC on scholarship, you must plan on being a STEM major. It is my understanding (someone correct me if I'm wrong) that you will not get a scholarship as a humanities major. NROTC is a very competitive program (for a scholarship) -- and you must also be accepted to the school itself. It's a different way to become an officer, but not necessarily an easier one.
There are quite a few military folks who go on to careers in politics. AFTER their service. Sadly, a small number go into the service to boost their resumes, so to speak. Join the military because that's what you want to do. If your desire for politics still pulls you, then get out and pursue that dream.