Knowing the law is your friend. Glad you've looked into it.
Don't go into a K-12 school or Boise State. Don't go past metal detectors in the airport and don't try to go into the courthouse, and you'll be fine.
ANYWHERE else is legal. Just don't go waving it around at people and you'll be legal. It doesn't matter that you're not an Idaho resident either. You're legal. You might get hassled, mostly because of your age, but I highly doubt it... there're a lot of guys your age OCing up here now! Stay safe! Condition Yellow always!
Enjoy your stay!