Hey welcome to the community! i have Armani Code and it has been one of my favorites since the day i got it. this was the first fragrance i bought and wore for myself. projection on me is good. i get around 3 hours projection and then it starts to tone down. longevity is great with this fragrance. i normally do one spray in the front of the neck, one in the back of the neck, and one on the chest. to me thats more than enough. as for is it okay for a teenager to wear this? of course! I'm a teenager as well and i love wearing this fragrance. Hope i helped you!