New Hairstyle? but is it right?

HelloI have a roundish-squarish-ovalish shape.. i'm not for sure.ButI don't know how this is going to effect the hairdo i really want to get. I want to get one that short..kinda layers..softly.. it's right above the ears..but then kinda shaggy like. It would be at the nape of the neck/head.I have kinda Thick wavy brown hair.. I saw this girl at the mall with this haircut and it was so clean and pretty looking. I've had my hair like meg ryan or it was supposed to be..but i don't know if the stylist really knew what she was doing..or maybe it was just wrong for my hair?i don't have tiny facial features.. but sort of a broad nose.. i don't mind anything else.. and my nose don't bother me all that much.. i just don't know how it would effect the look of the style i wish to have. I don't want my hair any longer than my shoulders. i hate the way it looks. in fact my hair has grown out since i got it last cut in february. and i now pull it back awaiting this friday when i wanna get it cut....I'm 16 years old so i want something new and up to date.thankyou for your time and i hope you can help me somehow.sincerely thankful and Eager!