Help with daily calorie amount

Put your stats into MFP - set your weekly weight loss goal according to the list below

Pound per week goals
75+ lbs set to lose 2 lb range
Between 40 - 75 lbs set to lose 1.5 lb range
Between 25-40 lbs set to lose 1 lb range
Between 15-25 lbs set to lose 1 -.50 lb range
Less than 15 lbs set to lose 0.5 lbs range

This will give you a calorie deficit with zero exercise. If you exercise, log it & eat 50-75% of those calories as well.

If exercise is something you routinely do, and you don't want the up down of adding workouts. Find your TDEE (total daily energy expenditure...aka maintenance including exercise) and subtract a percentage off.
http://scoobysworkshop.com/calorie-calculator/