Initially the faucet handle was stiff and very hard to turn ,now it will not turn at all.and is stuck OFF

Is this a single handle faucet or are there two handles, one hot one cold.

Two handles .one hot ,one cold

Shut off the supply to the offending handle and back off the nut on the tsem. Once the nut is loose you should be able to unscrew the stem and inspect. You might want to put a few drops of WD 40 on the stem just above the nut and allow to soak for a few minutes before you start.

In my attempt to turn off the water supply to the offending handle... the supply handle was also offended . I was able to turn the cold water supply hanlde w/o any problem. I will need to buy the spray WD-40 to reach the hot water supply handle to see if that will loosen it enough for it to be turned. I will spray it and wait a little while to see if that will loosen it up enough.I may need to wait for my son to get home from work to use his longer/stronger arms/hands/fingers. The hot water cutoff is behind a long horizontal pipe and I can't quite reach it to get a good hold of it, but either way it should have turned a little bit one way or the other (righty tighty /lefty loosey )...

Thank you for your help though (so far)..
I hope to report back much success

Yep "righty tighty /lefty loosey " so you are turning counterclockwise to say it differently. Some fella actually makes a big red cap that fits over stop cock handles to make them easier to turn. I must be getting old, I own one.