Weight loss help

I am a 23 year old woman, I am 5ft3 and 149lb. I really want to get back down to 110-120lb. I have a newborn and I don't exercise alot at all. I'm eating 1600 calories a day is this enough to lose weight without exercise or do I need to lower it? Does anyone have any advice? Any simple quick workouts that are effective? Would love to hear some stories for motivation!