I've been smoking for 4 years and I still don't want to go high to class in classes where my teachers would know.

Smoking for your first time should be in a house with your friends incase somethign does go wrong (allergic reaction... green out...). Also you don't necessarily get high for your first time, I hit about 3 bowls for my first time from my friends bong and I was perfectly sober.

Hope it helps.
Ferg