Just my opinion, but trying to lose a specific amount of weight each week can lead to frustration. I think 2000 calories a day sounds perfectly reasonable to begin losing weight. Try to move a little bit, eat 5+ servings of vegetables a day, eat fruit, lean protein, low fat dairy, whole grains, try to limit the amount of packaged/convenience foods you eat. Be patient with yourself, give it a month or so (since vagaries like TOM and such can seemingly stall weight loss efforts). If the scale still isn't moving after a truly reasonable period of time (longer than week), make a gradual change to 1800 a day and repeat the process