Don’t just stop at the calorie listing on a nutritional label. Calories are important (as are the other macro and micro nutrients), but you should always take a closer look at the ingredients to know exactly what you’re putting into your body.
Ingredients are listed by quantity, from highest to lowest. Try looking for products that list whole foods as the first three ingredients, and be skeptical of foods with long lists of ingredients. Also know that sugar and sodium have many different terms, so educate yourself on those if you are trying to limit them from your diet.