Yes, FR campaign setting will be allowed also the players guide (I think that's what it's called) will be too, but nothing else. I ran a party from 1st to 150th level over many years until I killed them off, if that's counts, I also have run this path many times as well, with my various groups at school. so a fair amount of experience.
I'll put the hook for the first adventure here:
The first savage tide has already touched the mortal world, yet none who live today recall this time of red ruin. Unleashed from the cruel heart of a fell seed known as a shadow pearl, this savage tide swept over an ancient city perched atop the crown of a remote island. The tide transformed beggar and noble, merchant and thief, resident and visitor into feral, ravenous fiends. The fruits of centuries labor came crumbling down in a matter of days, and when survivors tried to stem the tide by destroying the pearl, the resulting blast of power sunk their city into a boiling lake of death, through it all the Abyssal architect of the savage tide watched, taking pride in the ruin. when the tides final; ripples had faded, what was left became know as the isle of dread.
Now a thousand years later, the true masters of the isle of dread look upon new targets, new cities beyond the horizon, compelled by the hateful will of their demonic lord Demegorgon to prepare for the coming glory. This time, the doom will not be limited to one hapless city. This time, all of civilization waits unknowing on the shore, blissfully ignorant of what the incoming tide brings in.