To practice: your camera should have a night landscape mode. Make sure the flash isn't on in that mode (shouldn't be, but double check). Go around someplace safe at night when the buildings are lit but not the whole area, like a parking lot. Take pictures while walking slowly (you can't stop), and see how your camera responds. Each one is going to be different, and I'm not sure how high your ISO can go, and how fast your lens can go. Take a look at the pics and see how they came out after you've gone around someplace doing this.