Hi there, Le Woon! Thanks for stopping by planDisney with your question!
I'm so excited that you are planning a trip to the Disneyland Resort this December! So much magic and joy await you at the parks! I'm hoping that an announcement comes soon about the official release date of
Disney Genie and Disney Genie+. In the meantime, if you purchase your tickets today, you can most certainly add on Disney Genie+ when you visit in December. Each day you visit the parks, you will use the
Disneyland app to purchase Disney Genie+ for that day. The cost will be $20 per day, per ticket. If you wait to purchase your tickets until after Disney Genie+ goes live, you will have the option of adding Disney Genie+ for the duration of your ticket at the time of purchase.
When it comes to purchasing individual attraction Lightning Lane access, you will also make those purchases on the day-of in the Disneyland app and the cost will vary. Individual Lightning Lane access allows you to reserve up to two return times per day for three highly-demanded attractions that are not part of Disney Genie+. Those attractions are Star Wars: Rise of the Resistance, WEB SLINGERS: A Spider-Man Adventure, and Radiator Springs Racers.
I hope this information was helpful. Have a fabulous time at the Disneyland Resort!
-Linda