First of all, good luck and take care of yourself.
Second thing, you have to take into account only one thing,
Your commander, three years older than you,
He is a man just like you and no more than that (proportion).
After basic training, you'll understand what I'm talking about.
As for discipline, you have no choice now, it's an army,
You will have to change or stay a lot of Saturdays at the base.