Let's face it. Not everyone is going to be the poster child of extroversion, not even some extroverts. Introverts on the other hand? You're going to have a different experience than your more outgoing friends, and that's okay. Here's how I survived college as an introvert.
Is this the Union at noon? No? Either way, it's pretty close.
I avoided the Union like the plague around noon. Why? Everyone is there. All those kids from your class, one kid from your dorm, and one kid you somehow know? All of them are there. Not only that, but good luck finding a place to sit alone. Every seat has probably been taken. Come here in the early morning or later afternoon if crowds aren't your thing. The Career Center and higher floors are also less crowded but have fewer seats.
Higher floors being less crowded seems to be a trend. The upper floors of the Union have few people, the upper floors of most buildings are quieter, and the top floors of the library is fairly empty until finals and midterms come around. Take advantage of these and find a secluded spot. Your search might even include lower floors of the library, which often have fewer people than the upper floors. Also, search buildings that most people either don't like, don't go to, or don't know the way around, i.e. the Eppler buildings. Ask any student on campus, and they'll probably say that Eppler is confusing and they dislike it. I agreed until I had 2 classes on opposite sides of the building. Finding a spot up there is easy, and you can get a great view.
Basically your view if you get to classes early.
I got to all of my classes early, while other students were still in class. Instead of being in rush hour in the 10 minutes between classes, going even 5 minutes earlier can get you there fast, uncrowded, and relaxed. If you only take one thing from this, get there early.
Go to something, even if it's just a group study session.
Lastly, you don't have to go to everything. I didn't go to a single party, and while it may seem uncool, it saved me a ton of stress. I found my niche as early as I could and I stayed there. Mine was the Arts Village (which you should join if you have any interest in art, shameless plug), but yours can be anything. While you don't have to go to everything, force yourself to go to at least one thing every month. Get out of your dorm every once in a while, and open up your door sometimes if you feel safe enough. College does not have to be any more stressful for introverts than it already is. You can do great things if you don't let introversion stress you out.