If you do NOT have a power (electric) radio antenna that was a factory feature on your Camry then the power antenna output on the new head unit will NOT be used. Secure the end of the lead with a wire nute or something to keep it from shorting to ground when the tuner is active.
Look for a cable that looks something like the picture that cjjackson posted above. The end that looks like the right-hand end of CJ's picture will connect to the rear of your head unit (in the only input port that looks remotely like it might accept such a connection) If this cable isn't connected you won't be able to receive broadcast radio stations clearly unless you're very near their broadcast facility/tower.
The mute wire on your head unit is another wire that will go unused unless you have a permanently-installed hands free cellphone setup in your car that has an input for such a thing (causes the stereo to automatically mute itself when your phone rings)
The system remote control wire is your remote turn-on output. If you were running external amplifiers/crossovers/EQs that you wanted to have turn on and off with the head unit you would connect the sys. rem. con. wire to the remote input on the various outboard gear. If all you've done is replace an OEM stereo with an aftermarket unit and you aren't running anything else then this wire will go unused as well. Secure the ends of the system remote wire and the mute wire as described above, get the antenna plugged in (that cable is behind the dash near the place in your console where the radio mounts, I promise) and you're done.