Hey, Tyler - welcome to the mad mad mad mad world of digital photography.
So far, you've gotten some good advice here. As most have said, comparing Canon and Nikon always brings out the brand fans, but that's okay.
Part of your quandary is that you don't have enough money. Well, join the crowd. Photography is not for the light of wallet, but you also own a tool with which you can make money. Think about ways you can make a buck or two with your new camera, then put that money away for the next lens or body or tripod or ballhead or filter or flash you just
gotta have. You might see if the local weekly newspaper could use a freelancer, or maybe you go work as an assistant for a professional, or maybe shoot some of your high school sports and sell the prints.
You mentioned shooting fireworks, and there is some good advice from Howard. Another source is this article on
The-Digital-Picture.com.
Oh yeah - we expect to see some of your shots when you get back from New York. Have fun.