Yes, it is a teen book considering nearly all of the main characters are indeed teenagers. The only real thing to watch out for is all the death and violence. However, the language is decent and the farthest the characters ever go romance-wise is kissing.
I am a grandmother. I have read the book at the urging of a granddaughter. It was excellent and I would refer it for young children. it is fast moving and exciting. a good book for young people. and I think you will like it too.
I think its okay, but when you read a book when you're younger, your experiences and knowledge will mean that you interpret it differently; make sure you read it again when you're older, because it will affect you differently. It doesn't really matter how old you are to read the Hunger Games, because its pretty much appropriate for anyone.