Zumba runs roughly an hour. You will have a warm up, then interval type cardio and a cool down. You will use common Latin dances: salsa, cumbia, cha cha, meringue, etc. Some instructors will incorporate hip hop and reggaeton depending on the music they have chosen. I try to mix up the music, and the choreography so there are parts where you can feel the transitions in the music. Every song has a dance that follows its' beat, so after a while you will hear a song and say, "That is salsa." There is very little talking by the instructor, but as you go to their classes you learn to pick up their cues for the music/move changes. There is lots of energy and smiles and fun. Most instructors in Salt Lake give a week or two of free classes so you can try it out. I have heard that some people come out the entire week before they really get the hang of it. I bought the videos and did it from home for a few months before I ever went to a class and I felt pretty confident that I had the basics down.
It helps that I am from Los Angeles (will I be crucified for admitting that?) and I grew up with a lot of these dances.
I would encourage you to go for it, but I am biased.