1998 IMAC Questions ?

I got this from a friends mom who was getting rid of it, Im pretty sure its the first one not the more new ones to come after that, this has the 32 Ram and 4GB hard Drive and its Green. Ok I DO not have the Disks for it, I got a copy of Cheetah on a CD but when I try to Boot up with it on the Computer it does nothing. When I try to use the OS 8 is that i think it is on the IMAC I get an Error saying Finder cant find somthing so it goes no further then that, So I really would like to get some use out of this thing still. So I got the Idea to put Cheetah on the extra Hard Drive I had its a 15GB hard Drive, put it on my New IMAC Erased it as Mac OS Extended put Cheetah on it no problem from my Intel IMAC then put the Hard Drive back on the Old one, tried booting up and it doesnt see it i thought it would be worth a try. So would I beable to somehow get this running at all without haveing the Original Disks I really do not feel like hunting down CDs if its not even going to work. If anyone knows how I can get it workin that would be awsome. And does this Read Burned CDs I dont think it does