If you major in Italian, you will - of course - become fluent in speaking the language. You'll probably spend a semester or two in Italy, too. Or, at least, you should. But all that is just the tip of the iceberg.
The study of a language at the college level is not limited to the memorization of words and verb conjugations. If you major in Italian (or any other language) in college, you'll study history, art, politics, and everything else that characterizes the culture of the places where it's spoken. After completing several required courses in Italian grammar, composition, and conversation, you'll choose from a variety of classes in Italian literature, advanced translation, and civilization. In a nutshell, your courses will cover everything Italian - from Dante to Fellini, from Spartacus to Mussolini.
You won't run out of topics. The people and culture of Italy have contributed a great deal to the arts, political theory, literature, and religion of the world. There's Michelangelo (who painted the Sistine Chapel), Leonardo da Vinci (who painted The Mona Lisa), Galileo (one of the most important scientists ever), Machiavelli (who wrote The Prince), and Dante (who wrote The Divine Comedy), just to name a few. If you choose to major in Italian, you will spend four years studying the great works of Italian culture - in the original Italian no less - which have contributed immensely to the history and culture of the world.