How fast could I get a six pack?

I’m 15 years old and kind of chubby in my stomach. Every Monday, Wednesday, and Friday I workout my abs by doing 3 sets of 6 different crunches(Which I do 20 each). During Tuesday, Thursday, and Saturday I workout my chest by doing 4 sets of push-ups, which I do each set until I can’t do anymore. I also do cardio because I’m in the track team for my school, we have practice 5 times a week. Also, the only thing I really eat is cereal for breakfast, a sandwich and chips for lunch, and anything my parents cook for dinner lol. So having said that, how long will it take me to get a six-pack??