Hi Ronda!
Welcome to planDisney.
All guests can visit Magic Kingdom from the usual opening time at the park until the official opening of the party. If you don't have a ticket for
Mickey's Not-So-Scary Halloween Party you will be required to leave by 6.00pm. Every guest is also permitted to make dining reservations - like yourselves - at a restaurant inside Magic Kingdom up until 5.55pm - if available - (for Cinderella's Royal Table or Be Our Guest Restaurant, for example). Please know that as soon as you have finished your meal you will be escorted from the park - no shopping, or stopping for photos, so remember to make all your purchases and get all the photos you need before you sit down at the restaurant.
Party guests can enter
Magic Kingdom any time after 4.00pm, even if they don't have a regular admission ticket for the park, and will be identified by a special party wristband. The party officially begins at 7.00pm.
When there is a special event during the evening, the park can be quieter during the day, as some guests would rather save their ticket for a full day when they can stay until closing, and enjoy the fireworks. If you don't mind having a shorter day you might enjoy reduced wait times around the park, and you can still make your Lightning Lane purchases if you wish to do so (but it's possible that you might not need them).
Please come back and visit us if you have any further questions, and you can
send me a direct question if you wish. We are always happy to help you plan your magical vacation to Walt Disney World!
Sue