Ok Im 169lbs, 4'11, 4 Kids, My Ideal Weight Goal

ok im 169lbs, 4'11, 4 kids, my ideal weight goal is 120, i have three lbs of fat on my stomach. im new to the fitness world and have no clue where to begin with fitness. also, i heard having a orgasm its possible to lose 20lbs of water weight, is this true? cant have a orgasm anyways just curious....