The SLFA (speedlite foot adapter) is to add a sync connection to a speedlite via the foot. You will need its counterpart, the HSA (hotshoe adapter) to mount to your camera in order to connect the flash to your camera.
http://www.paulcbuff.com/hsa.php Alternatively, you can use a radio remote, such as our CyberSync line, to wirelessly trigger the lights, even without line of sight.
http://www.paulcbuff.com/cybersync.php In the mean time, you can use the pop up flash of your camera, but you will need to set it to the manual mode. (Nikon cameras should have that option in the pencil menu tab, under "built in commander settings", or similar heading).