[Bean 2]

I was wondering because i really want to build my chest and abs but i dont know what workouts to do. My workout now consist of 50 twist situps followed by 20 side situps(lay on side and sit up), two leg lifts for about 30 seconds, two sets of 30 push ups, and then free weights. Im looking to build my chest and abs but i have to do it without machines or weight or anything. What areas do pushups effect?