Hello, Christine!
Great news! According to
Disney Parks Blog, the preview of the New Fantasyland expansion, which begins on November 19th, Guests will be able to make reservations for Be Our Guest Restaurant sometime in late August!
I suggest that you do two things to help you secure a reservation to this restaurant, which is sure to be very popular. First, subscribe to Disney Parks Blog so that you'll be among the first to learn about updates such as reservations being made available. Second, contact Disney Dining at (407) WDW-DINE and talk to a Cast Member as early as you can on the date that reservations can be made. Tell the Cast Member the times you'd like to dine (you may need to be flexible) and the dates on which you'll be there. I suggest that you take the first acceptable reservation that comes up, if you are fortunate enough to secure one. If you'd prefer a different date and time, continue speaking with the CM in order to look for a reservation you like better; secure that one before asking the CM to cancel the first. (I have had openings snapped up by other CMs while trying to decide if that's the best choice for my group, and with a restaurant opening so closely to your arrival time, they are sure to book up quickly!)
Best of luck! Be sure to send more questions as you think of them, too! We love to help!