Hi @Vamsi234 the day begins at midnight and what you're seeing is your BMR. We all burn calories, even while sleeping. It's normal, so don't worry about it.
Those are your BMR (basal metabolic rate) calories that you are always burning just to stay alive. They are always credited, even when you are not wearing the tracker. They contribute steadily all day; the 500+ you see in the morning would be your BMR calorie count so far since midnight. There is no way to exclude BMR calories.
See How does my Fitbit device calculate calories burned?