Hello Allison! Welcome to the Disney Parks Moms Panel.
There is no better way to start a day at Magic Kingdom than with
Advanced Dining Reservations at a Character Breakfast like Fairytale Dining at Cinderella's Royal Table.
With the
Let the Magic Begin Welcome Show at Magic Kingdom, Main Street, U.S.A. is open to all Guests (regardless of staying at a Disney Property or not) roughly 25-45 minutes before official Theme Park opening. Several venues, including
Main Street Bakery and some of the shops on Main Street, U.S.A. are open at this time for some early indulgence (mine is coffee). Theme Park Admission is required.
If you find yourself at the Main Gates of Magic Kingdom before Main Street, U.S.A has open, there is a special queue and entrance for Guests with early morning
advanced dining reservations or
Special Events and Tours that start before Magic Kingdom is open. In my experience, the queue is on the very far left next to The Newsstand Store and they usually have a Cast Member with a Sign indicating Early Entrance for this purpose.
Either way, you should be fine getting to your 8:45 am reservation at
Cinderella's Royal Table in time. Just be sure to arrive at the Ticket and Transportation Center early enough to get through Security Clearance and take the Monorail to the Main Gates.
Have a Magical Morning!
~Todd