ve never tried dieting, counting calories or carbs, etc, you might want to check with your doctor or have her/him refer you to a
nutritionist or
dietician, who can make sure you get the nutrients you need and can also explain what constitutes carbs, proteins, fats and other nutrients.
You will also need to start an exercise program that's appropriate. Start slowly, by taking a brisk walk for 30 minutes daily, then increase as you can.