Kim the app should set the calorie count for you, depending on the amount of weight you have to lose and the goal dates for losing it, your current weight, height, age, activity level, etc.
If it's not setting, you might have your goal dates too close together.
Kim, you can't set anything on here, except a "goal weight". You have to track your caloric intake, which you can then post to the weight tracker, and keep track of it in that manner. Hope this helps