Remote start is on a premium QX60. Look at your key fob, and if there is a circle looking button above your lock button, that is remote start. The only way you wouldn't have it on a 2014 or 2015 would be if it was a non premium base model.
If you do have the half circle button above the lock, all you have to do is tap the lock button, and then hold the circle button for about five seconds. You will still need to put your foot on the brake and hit the start button before you put it into drive though otherwise it will shut off. Let us know if you can't figure it out.