Non binary:What does it mean? and questioning myself

I'd describe myself as gender non conforming.Im happy being a girl(im 17,so i prefer using that word instead of woman,as woman sounds more grown up in my eyes).But I'm exploring a bit currently and taking my time,you could say.Im still trying to understand the differences between the two.Im a bit discouraged though,as people on the Internet and stuff(mainly YouTube,god i hate Blair White and a bunch of others) say that non binary isnt real,its NLOG behaviour,etc.Its frustrating.

I'll reply when I can.