Marathons are long-distance running races of over 26 miles and are great exercise!
Wow! thats cool! Ive been actually training for a marathon recently, DO you know if a marathon is on a flat road or are there any hills? 
I think they are generally flat, but the event was made to commemorate the run of Pheidippides, a Greek soldier who relayed the victory of the Battle of Marathon to Athens.
Oh ok, I just hope it wont be too hard, I can only run so much up a hill lol. What kinda age limit is there for a marathon i any? 
There aren't any age limits. In fact of the more than 800 marathons held in the world each year, the majority of competitors are recreational athletes.