Workouts!!!

Diana • Not TTC at the moment .
I began working out as of recently. 
I go on the bike for a mile and a half and I do butt workouts as well. I haven't started on my abs and such yet.  I'm not chunky or anything but I definitely want to tone my abdominal area. I also didn't set up a meal plan or anything. 
 
If anyone can help me answer my questions:
-How do I tone my stomach ? 
- how/ what should I eat ? 
- should I use a supplement to fasten my results ? 
Thank you for all your help! 
Btw: I'm 5'8 and 134 lbs