Listen to the type of music rhythm you're trying to learn for a week before you start worrying about the rhythm. You may find that your body discovers the rhythm on its own and starts moving naturally to the music.
Watch dancers moving to the music, if possible---whether in a dance club, at a dance studio, or in a movie. Listen for the drumbeat, and notice how the dancers' bodies mimic the rhythm of the drum.
Practice moving different parts of your body to the same beat the dancers are following. Try using your fingers, your hands, your toes, your hips, even your facial features. Notice that you can follow the beat with any part of your body, or even several parts at once.
Stand up and practice doing the most basic dance step associated with the rhythm you're trying to learn. You might be brave enough to do this in the club or a dance studio, or you might want to practice in front of a mirror at home first.
Listen to the drum beating in the music as you move, and let your feet follow the rhythm just as your hands, toes, and other body parts did before.
Practice using other parts of your body to add more expression as you continue the basic dance step. You've already learned the dance rhythm---the more you practice, the more you'll be able to do it without even thinking about it.