Hi, Rosemary!
That's thrilling that you'll be on the Westbound Transatlantic Cruise aboard the Disney Magic. I've never taken a Disney cruise for that long -- so you'll have to be my "go-to" person if I'm ever that fortunate!
I'm really not certain why you can't access more than one night to book dinner reservations at Palo online. Of course, you are well within the window of time to book -- even for first-time Disney Cruise guests. And if you can book one night, it means that you have already paid for your vacation in full.
My suggestion is to log out of the
DisneyCruise.com site and then log back in again accessing your reservation. Go to My Cruise Plans on your reservation and scroll down the page to see what is available under "Reserve Activities." If you're still having problems, call Disney Cruise Line at (800) 951-3532 or (800) 449-3380 for Castaway Club Members. You will have the option to request site help by phone.
I hope that helps. Let me know if you have any more questions. Have a wonderful day and a magical vacation. Bon voyage!
Andi