I have a (17-inch, early 2006) iMac which, like your Mac, is a 32 bit machine. I downloaded the file
Fedora-Live-Workstation-i686-23-10.iso from Fedora. This is the "32-bit 1.3GB Live Image" found at this web page. Next, I burned the file to a RW DVD. I inserted the DVD in my Mac and held down the option key at startup. A DVD icon label "Windows" appeared. After selecting this icon, the computer attempted to boot to a live version of Fedora. This failed.
Next, I tried booting again and this time, when prompted, I selected "Troubleshooting". From the menu that next appeared, I selected "Test this media & start Fedora Live". This led to a successful boot of Fedora Live.
Note: With Fedora, if I leave the computer unattended for a sufficient amount of time, the computer will go to sleep. To wake, I needed to tap the power button.
I did not attempt to install Fedora, but this option was presented to me.
Note: This version of Fedora requires a BIOS to boot the computer. My computer was shipped without the ability to BIOS boot an operating systems. I needed to install a firmware update to enable this type of boot. The web site for such updates is "About EFI and SMC firmware updates for Intel-based Mac computers". To install such updates, requires OS X to be installed on your Mac.
If you can not boot from this DVD, the solution may require applying a firmware update to your Mac.