When you mark your meals as eaten and record your water intake, you'll find weekly breakdowns of your nutrition intake on the profile screen.
If you're using another calorie tracking app, make sure both that app and MealPrepPro are syncing to Apple Health. MealPrepPro will pull in all the nutritional information from Apple Health and add it to your charts.
To integrate MealPrepPro with Apple Health, tap on Profile > Health Sync and switch this to on.