Its hard to say. A friend can say that they think it'll be cool, but also someone who likes you could say that too. I think you should do it if you want to. Personally I don't like them, but I'm sure there's some girls who do.
I personally do like it, at my school there's a senior with a beard and all the girls from my class think he's hot we're junior. He keeps it long and it's pretty soft, I guess with him the caveman style really works out. It's all about hou you handle it and your personality.
Being 17, I personally prefer no facial hair, or a maybe a little stubble because I like the youthful look. But I don't like when it's all prickly and hurts when you touch it, facial hair can look really sexy on the right guy though.
I personally don't. I still have a lot of people I knew throughout grade school in my school, so seeing them with facial hair makes me cringe. For some reason facial hair makes guys seem less well kept/older (in a bad way)- I guess it's my male equivalent of seeing girls who don't shave their legs- I don't hate it, it's a natural occurrence, and I get that-I just prefer clean shaven men.
I think most girls do like beards. The problem is they all like different styles of beards so growing one may or may not help you. For younger girls I think many of them are just not use to dating a guy with a beard. People tend to resist what they are not use to. I have known several woman that hated that their man grew a beard. After a while the women have all grown to love the beards and tell the guys not to shave them off.