The Sony CCD TR 517 is an analog camcorder , not a digital camcorder and therefore you would need to use an analog to digital converter in order to capture your video into iMovie .
As your camcorder is analog it will not have a FireWire port , so don't try looking for the FireWire cable that didn't come with it .
You would need to connect the video and audio output of the camcorder to the input of the analog to digital ( A to D ) converter and then connect the output of the A to D converter to your Mac.
Do a search for camcorder A to D converters on the internet if you wish to pursue this . Just be sure that it is Mac compatible.