Will i lose weight if i?

will not eat anything sweet and eat less rice(2 cups/day) but still eat loaf bread(not whole grain or anthng maybe 4 loaves/day bec, it's my breakfast) and still eat meats(pork, beefs hotdogs) walk 10-15 mins a day. will stand or walk for 30-45 mins. after eating. i'm not over weight or anything i just want to lose some flab in my stomach. will crunches really work? how many crunches should i do what time of the day? like afternoon? morning? and what foods should i avoid or cut off. btw i'm 17 y/o grl.