Today I got a used "Next" Power Climber bicycle in extra fine condition and have a problem getting the front shifter to work. You shift it on the left front handlebar by twisting it either forward or backward. It seems to click but the chain is not moving. It seems something inside the twist mechanism is not working correctly. Does anyone know what I may be doing wrong and how I can correct it.
The shifter on the right handlebar works perfectly by twisting the shifter mechanism making it shift up or down. Now problems at all with the rear.
The front sprocket has the chain on the smaller sprocket and no amount of twisting on the left handlebar has any effect on moving the chain. Any replies will be appreciated.

Step one, check if it's the shifter or maybe a cable issue. Pull the wire away from the frame like a bowstring, then work the shifter. If you don't feel any cable movement, then it's either a broken shifter, or possibly the cable's head isn't engaged. OTOH, if you feel cable movement, then it's simply a matter of pulling out all the slack, and resetting the cable at the Ft derailleur pinch bolt.

FBinNY will try bowing the cable but I do not feel it is broken or stuck. Will check back in a few with the results

FBinNY just tried what you suggested and the cable is not broken and when I bow the cabel and twist the shifter I can feel the cable get tighter or looser just according to which way I twist.

Another question, when you pull the cable like the bowstring, and you are pedaling with the bike on a stand or flipped over, does the front derailleur actually move and possibly shift?

What you would be doing is using your fingers to pull the cable like the shifter would normally be doing. You want to see if the front derailleur shifts normally.

And when the shifter is at 1, is there any slack at all in the cable? There should be very little slack.