First Battalion Ball

Hey there! So my boyfriend is in the US Army and he's invited me to his Battalion Ball this November. I am a 17 y/o college Sophomore, so my first question is will I be able to attend as a minor? As stated this is my FIRST Ball attendance as well as his and I'm wondering if any of you ladies have advice for me. I also want opinions on the dress I want to purchase, such as it being appropriate for this kind of event.

Here is the dress, I can purchase it in any color so my top choices are navy blue, dark green, or maroon (I am a natural redhead so if you have any other color opinions you think might look good please let me know!). I know it is slightly revealing but I do plan on purchasing a shall to wear for the ceremonial parts of the evening.