what year/month did the build for the click (i mean just HHH n HBK in the storyline) start??? like when did they first get brought together?

I always considered the MSG Curtain Call the first official sighting of the Kliq, and that was '96, and that was right before Hall and Nash jumped ship. There might've been a few tongue-in-cheek allusions to the power brokers prior to the Curtain Call, but I think that was the first actual time they broke character and showed allegiance to one another on camera.

they'd been friends almost since HHH arrived

-- Nash stated that he 'adopted' HHH to be the group's Designated Driver, as HHH was not a drinker, while the rest (HBK, Nash, Hall, Pac) had been pretty wild partiers at the time

the others had been friends pretty much dating back to HBK and Nash's on screen alliance when he arrived

as to HBK and HHH going public with their Bromance, they'd been pushing for it behind the scenes since late 96, but it only happened in summer of 97