Following the proper diet and good workouts are enough to cause weight loss. Cardio is often overdone and overrated.
The best way to do cardio (if you are not already doing any) is to either wait a few weeks to start... or start slowly and increase a little every few weeks.
Never start out doing a lot of cardio, it's a good way to get burned out. Focus most of your workout energy on your workouts. Your workouts (done at a fast, non-stop pace) will burn more calories because you are working all of your muscles.