I am a 15 years old girl. I am 164 cm tall and 58 kilogram in weight. Am I fat ???

No not at all that's a perfect weight. And you're still young so you probably have a nice slim body or you may be curvy but I'm sure you look great and really beautiful.

You can't put yourself down because of weight, also people who talk about a person's weight is just being ignorant. You're best to consult a doctor, not someone with poor judgement on the Internet..