I would say that if you wanted to tone your abs you should stay away or try not to eat alot saturated fats and trans fats which are commonly found in junkfoods. Instead I would opt for more healthy foods like instead of eating condensed food and junk food mfor a snack try a variety of fresh fruits, muffins,etc. Also limit your consumption of greasy foods like pizza because it makes you tired while working out. And its not very healthy.
while toning your abdominals I would say that you should try some oblique twist crunches which would work the sides of your abs. Also I would say that for toning your lower abs you should try some straight leg rainbow crunches. And lastly for your upper abs you should try some scissor kicks. All of these exercises can be looked up on this website. Also for the best results you should try to do 50 reps of each of these exercises daily. But if you can't then I think 35 reps of each should work too possibly. Good luck hope this helps!!