Is it weird not to have a best friend in HS?

No it's NOT weird. It only means you are more cautious about who you trust, which is the best thing to do nowadays. I have close friends too, I'm 23. I had a "best friend" but that's only a title.... TRUE FRIENDS will be there for you weather they have the best friend title or not, and when you really need someone to talk to they are the ones who go out of their way to be there for you.