Question

First the most important thing is your diet.  Since you left out details of your diet, I'll tell you that in general I recommend a calorie restricted ketogenic diet.  For example, this means that if you were accustomed to eating 2400 calories/day, you will now starting reducing it by 200-300 calories per month until you are around 1200 calories or perhaps less.  And because it's ketogenic your ratios would look like this:

• - 70-75% of total calories from Fat
• - 20-25% of total calories from Protein
• - 5-10% of total calories from Carbohydrates

Let's say you set your total calorie intake for the day to be 1500. Here's one way to calculate how many grams of fat, carb and protein to eat:

1500 x .70 = 1050 calories from fat.
Fat has 9 calories per gram = 1050/9 = 116.5 grams of fat. (Reference: 1 tablespoon of butter has 12 grams of fat.)
1500 x .20 = 300 calories from protein.
Protein has 4 calories per gram, = 300/4 = 75 grams of protein. (Reference: an ounce of meat has 7 grams of protein).
1500 x .10 = 150 calories from carbs.
Carbs have 4 calories per gram, = 150/4 = 38 grams of carb. (Reference: 1 slice bread has 25 grams of carb.)

Second... Exercise:
The most important part of exercise is INTENSITY.  While steady state, low intensity exercise (ie. "cardio" such as walking, running, etc.) is beneficial for some calorie expenditure, it really doesn't do much else... unless you simply enjoy walking or you dog could use a lap around the block - then by all means - GO!  But in general cardio does not give you the most bang for your buck. By that I mean it's not the most efficient use of your time or effort.  For example, if you road a stationary bike or walked on a treadmill for 30 minutes you would roughly burn about 300 calories... or about 2 slices of bread.  That's it.  The moment you get off the bike or stop walking the boosted calories expenditure stops as well.

But on the other hand, if you training focused on intensity (meaning high level of difficulty and minimal to no rest) lets say doing a 30 minute high intensity weight lifting circuit (again with minimal rest), you would not only nearly double your calorie expenditure (if not more than double... depending on your level of intensity: 500-700 cal.), you would have the added benefit of further caloric expenditure after you train, as your body responds and recovers due to the intense stimulus you provided.

So to summarize:

• - Correct dietary lifestyle is most important. (again I suggest a ketogenic diet at a moderate caloric deficit)
• - "Cardio" is optional... do it if you enjoy it.
• - High intensity training is a much more beneficial form of exercise, and necessary if you want a more sculpted appearance, stronger bones and muscles, and healthier cardio/pulmonary system.