Yeah unfortunately, they thought it would be a good idea to disable fastboot in the lollipop firmware. So if you're sure you're set up correctly to issue fastboot commands but they are not processing, then life just got a whole lot more difficult. Just for reference, when you type a command such as fastboot reboot, you should see those exact words output on the phone's screen. The problem is, it just doesn't perform the command. It knows you typed it, just doesn't process it into an action. If that describes your case then here's your less than simple fix:
http://forum.xda-developers.com/sprint-lg-g3/general/guide-fix-hard-brick-recovery-guide-t3132359
You've got a long way to go before you can use a kdz. And for this process you'll need a tot instead of a kdz.