I think I'm in love with a younger boy.

Okay, so I spent a weekend in the woods with my PE class, and there was this guy I really liked. I didn’t talk to him much, but I just felt attracted to him. I can’t even explain it. And he doesn’t know, I don’t know how to approach him….
He is 16 and I am 17, is it okay that I like him?
Today I overheard that some of my friends called another (girl)friend of mine pedophile (joking), because she said a boy a grade under us is cute. I know they didn’t really mean it, but I also know that they don’t think much of younger boys.
When I did something embarrassing on the weekend and was like “omg, I was so weird” and freaked out over it my best friend was like ‘You know that I don’t care what they think about me. They aren’t interesting…more like younger brothers’
It’s so obvious that she wouldn’t understand….and I’m already a person that doesn’t like to talk about my feelings but knowing what she thinks makes it even harder :(
Oh and perhaps you could give me tips on how to get a bit closer to him;) I don’t know if he likes me back even the slightest bit…I’m so confused…help me please?
I also don’t know if I’m really in love, but I do like him….and always think about him. I don’t have any experience with boys, perhaps that the reason why he left such an impression….oh god, I just don’t know what to do :(

(I’m a girl, if you didn’t figure it out yet:D)