Hey, howdy, hey, Lindsey and welcome to the Disney Parks Moms Panel. I am so excited for your December Disney vacation. Mickey and the gang have the theme parks and Resort hotels decorated for the season and the weather is "practically perfect in every way."
Since you purchased tickets through a third party it would be best to bring the certificate to any theme park ticket window and have them exchange it for
an admission card. Technically, you should not need to do this once the ticket is
linked to your My Disney Experience account but I would play it safe and make sure there are no issues with your tickets. If you have a MagicBand or plan on
purchasing one either prior to or
during your trip, then know the MagicBand will grant you entrance into the theme parks as they are linked to any ticket on your My Disney Experience account.
Disney Dad Tip: Within the next few months we will see tickets go on sale for
Mickey's Very Merry Christmas Party. I love this event because Magic Kingdom Park is open late hosting Mickey's Once Upon a Christmastime Party, Holiday Wishes fireworks, Disney characters in holiday attire like Jack Skellinton Sandy Claws, lower crowds to enjoy the attractions without waiting in long lines and the delicious holiday cookies and hot chocolate. It is the most wonderful time of the year.
Lindsey, enjoy making many Magical Memories.
~Jason