How To Get a Flat Stomache in 71 Days?

Hey Im Lauren .Well I Have a Little Stomach but it's Flabby .Like I Wanna Get a Hard Stomach No Abs.Just a Flat Stomach .I Bearly Started Walking Like Four Days Ago. Two Miles Everyday .No Cokes,Water .I eat Fruit But A lil Bit Of Like Food My mom Cooks Like Spaghetti I Eat A little of it And i Drink Water Before i Eat So i Can Get A Little Fuller . I Do 100 Sit Ups Everyday But I Just wanna Know if Yall Have Any Tips ?On How to Get a Flat Stomach Thanks Guys .