Is it normal for my teenager to come into the house or a room that I'm in and not greet me?

I don't say hello to my family every time I enter a room so, yes, I'd say it's normal.

You said teenager right? Yeah, it's normal, it'll pass and it's not like she can ignore you all day, every day; you're needed.

It is often normal for a teenager to not be even civil at times.
But they often don't say hello.

If it bothers you, correct them, on the coming into the house, if they have been gone for some time, not just out in the yard. But for me, pick your battles, this one is not worth it.