there is no front or real focusing ring on a 18~70mm lens.
There is only ONE focal ring, and ONE focus ring.
To use focal ring, use your fingers, hold the focal ring and turn, you able to change the focal length of the lens.
To use focal ring, use your fingers, hold the focus ring and turn, you able to change the focusing of the lens, you view thru the viewfinder, to see the image get into focus.
For more detail instruction, please read your camera, and lens user manual.
hope this help.