First, you have not given your full itinerary - a JR Pass might or might not save you money. If you don't travel enough, a JR Pass can be a waste of money also.
You can buy the JR Pass (assuming you'd save with one) from nearly any big travel agency that sells tickets to Japan, or there are other online agencies that exclusively sell them. Currently you can buy one in Japan as well as part of a trial basis, but the cost would be about 15% higher.
The trial sale in Japan expires in March and there is no announcement that JR will continue it or make it permanent. I can't think of any legit reason why JR should not do so. But so far nobody knows.
you can buy the tickets of Japan Rail Way below URL.
Have a nice trip!
i understand but JR Rail Pass is just noe big train company here .do not worry
yes or you can be goggle JR Japan Rail Pass
no no no you can check Japan rail pass website clearly.not advanced 90 days .do it worry about that.you know you are Americans you can stay in Japan without Visa 90 days.do not worry