Soup will not give you the nutrition you need to keep yourself healthy.
Eating a cup of soup before a meal will help you eat less during the meal, as will eating a small apple, drinking a glass of water or vegetable juice.
Losing weight "immediately" is nearly impossible, so just start on a good healthy diet and stick with it. It will take longer to lose the weight, but you'll do it in a healthy manner.
Exercise is also very important, so whenever you crave food, try doing 10 minutes of exercise and see if the craving goes away; often we aren't hungry, we're just bored or lonely.
The only thing that would cause me not to follow that plan is soup has a lot of sodium. And you do not want that , if you do try Pintrest and they always have a ton of healthy recipes on there . Best of luck !