Nnew diet and im not losing weight please help!....10pts?

first off it has only been a week and second of all try to add a little bit of exercise. you can walk for twenty min or ride a bike it doesnt matter as long as your moving and your heart is pumping blood. in order to lose weight you must take off at least 3500 calories from your normal diet. like if your normal diet is 2500 a day then just take 500 off a day and that will equal 3500 hundred calories you didnt eat at the end of the week which is one pund. This is only for if you want to lose a pound a week. If you exercise that will burn calories as well so you can eat more as long as you burn more than you eat you are good.