No dancing today to start, but I think cardio equally important. I get out of breath so fast these days, I'm honestly just WAAAY out of shape. My plan is to have a 30 minute cardio session twice a week, maybe after 30 minutes of dancing from next week.
Cardio can be from running, swimming, etc. If I can get to the gym, my go to cardio is interval training on a treadmill using inclines as well. I burn twice as much calories and put in way more work that way in the same amount of time. Read about the different training methods and what interval training is here. That site gives you everything from running, jumprope, bike, to swimming, so you are sure to find a great method that you'll like.
If you'd rather do something at home by watching a video to see what to do, this is a simple one you can do, or just youtube high intensity interval training for cardio and see what you like.
Good luck, and stay fit!