First off, don't overanalyze.. not saying that you are, but it's normal for people your age to worry about things like personality, likes, dislikes, looks, whatever. The other answers to this thread proves it
It doesn't really matter, I've had a few girlfriends. Most don't have the same taste in things as me, and it doesn't matter. Liking the same things is good for friendship and conversation. It helps in "picking up" girls, but matters less and less as time passes.
The cliche "Be Yourself" advice works. If you're being yourself, you'll find someone who likes you for who you are. If you have to act like someone else for them to like you, you'll have to act for as long as you're with them. Acting like an arrogant bastard when you're not really an arrogant bastard deep down inside will backfire.
But if you want advice: Look confident. People are wired to like confidence. There are those who like shyness, but it's rare. It doesn't mean you have to act like an arrogant jerk.. just talk confidently. Don't be hesitant, don't worry about looking stupid, stuff like that. It's hard, but hey, you have to start some time.
Emotions.. well, that's a normal thing at that age. I don't know why, you're just likely to get really emo about stuff. Just.. deal with it, I suppose.