It doesn't sound like your friend is being a good friend to you, but it doesn't sound like you're being a good friend to her either.
Friends don't have to always agree or have the same values or even live the same lives. Most of my friends are pretty different from me, and that can get difficult so I limit my time with them.
I personally don't think a 14 year old should be having sex, or dating older men, and behaving in other destructive ways. If you think your friend is in danger, by all means, speak up and say something. But calling her names and degrading her is not going to help. It not only makes her feel bad, but it also makes you look bad. Unfortunately you may not be able to do anything and you may have to let that friendship go if its too complicated to deal with. She is her own person and she's probably won't listen to your judgment in an objective way. Sometimes the way we learn is through the mistakes we make.
You are not 'doing wrong' by choosing to not have a boyfriend. Thats fine if you're not ready. But its ridiculous to think you never will. Nobody is 'bad' for wanting a boyfriend, just as no one is 'bad' for not wanting one. If you take care about yourself, you will always find someone who cares about you. When you're ready.