There are a few benefits to ensuring you level up this perk. You may have picked one of these up and thought I don’t need to craft one, or level up in the skill, but that would be wrong. However, you can place more than one turret, but only the closest one will work, unless that has run out of ammo, in which if another is close that will take over. To start with, you can only use one turret per person, until you have unlocked a relevant skill that will allow a second. But this doesn’t need to be done, the Junk Turret is completely self-powered, as long as you are within close proximity to it. The part that has people confused is powering the Junk Turret in 7 Days To Die.
Find a suitable place and right-click again to place the turret down. You will then see either a red or green version of the turret. If you are ready to use the turret, simply right click your mouse button, but make sure you have pressed R to reload it first. You will need to have crafted some ammo and then press R while holding the Junk Turret to make sure it’s loaded, once loaded, use it as if it were any other gun. Unless you happened to have it in your active Hotbar, you may not have thought to try using it as a weapon, but believe it or not, the turret can be picked up and manually fired.