You're shooting a wedding in only two weeks? Sorry to say this, but you shouldn't. If you're asking me why, it's because you don't have enough experience or knowledge yet. My guess is that all you'll do at the wedding is point your camera at the subject and then push the shutter button (i.e. point and shoot). So, bottom line, if you can get out of shooting the wedding, do it - you're just not ready..
Those "professional" cameras with long lenses are called DSLRs. Entry level ones start at about $500 usually, although real "professional" ones cost a few thousand dollars and more. But entry-level is probably what you need to start out, but I can't guarantee that the camera alone would do a good job for a wedding. My suggestions: Canon Rebel XS, Nikon D3000, Sony Alpha a230, Pentax K-x. Look into these those cameras. Narrow it down to the ones with the specs you want. Then head over to a camera/electronic store and try out the remaining choices. Whichever one fits in your hands more comfortably and is easier for you to navigate through is the "best" camera for you.
Now that we have the camera body covered, let's talk about lenses. For weddings, you NEED fast lenses. In other words, lenses with large max apertures. The reason why is because most of the time, using an external flash at weddings are distracting and prohibited. There are a few different types of lenses you'd need. However, the cost really adds up, so be prepared for that. Here are some lenses you'd want:
- Fast prime. Probably a mid-telephoto, 50mm, 85mm , etc. These are usually f/1.8 or faster
- Wide-angle lens. For when you need wide coverage.
- General purpose zoom. Probably needs to be f/2.8
- Telephoto lens. 70-200mm lenses are especially handy, FYI... And these probably should be f/2.8 as well or faster.
You don't have to get those exact types of lenses because the lenses you buy really boil down to your shooting style. However, two weeks is barely any time to figure out that shooting style.
Next time, know what you're getting into before you get into it!