People dance because they are inspired to dance by a beat or rhythm. At its most basic form, a dance might start with a foot tap to a catchy rhythm, and taking the movement further, it becomes a dance.
To be a good dancer you need to be able to feel the music and express that feeling with your body.
For the beginner dancer, it is important to become familiar with the rhythm, so get your hands on some music related to your chosen dance style and listen to it at every opportunity. Try out a few basic steps in the comfort and of your own home to build up your confidence.