My advice: Don't be obsessed about "passing" this interview. It is more important for YOU to ask questions, because the BGO (probably) knows the answers and can set you more at ease about what you need to prioritize from this time forward in the application process.
He or she has already seen some of the data on your application, and can offer guidance for continuing down this road to a commission in the Navy or Marine Corps. You will probably receive advice to have a "Plan B" and a "Plan C" as back-up (in case you are one of the MANY who do not receive an offer of appointment in the end). If what you ultimately want to do is be an Officer - there are several ways to get there - and all in the same four years that it takes to get through the Academy.
If the BGO suggests that your parents attend the interview, they should be coached by you to not speak until spoken to, and to be succinct.
This is
your interview - and even though
you're the perfect candidate - it's not the time for your parents to go on about how great you are.
Sure, they helped you a lot to get you to this point in your life, but it's
typically not them that the BGO is there to talk to.
I say
"typically", because in some cases, there are parents who are not keen on little Johnny or Sally joining the MILITARY. When this is a factor, a BGO can do a lot to set their minds at ease, and get out of the way for their son or daughter to do what they ultimately want to do with their lives.
BGOs are good at this, because they are on a peer basis with your parents and tend to be listened to better than you as
their baby!
You might want to rehearse some questions to ask your BGO, but you really don't need to rehearse
how you ask them. Just make sure that you ask questions that you really want answered. Don't ask questions that you think your BGO might want to hear. Just be you.
Lastly, thank your BGO. He or she is a volunteer. They do this because they want to do this. They want to meet people like you, who are some of the best and brightest our country has to offer. They are looking forward to meeting
you. How about that?