Greetings Donger! How exciting that you are a Disneyland Resort Magic Key Holder, I'm sure you're loving being able to unlock the magic all year long!
The great news is that being able to park hop is a benefit included with your
Magic Key Pass. You can make your
theme park reservation for your starting park of either Disneyland Park or Disney California Adventure Park, and then you'll be able to hop to the other park later in the day. You do not need an additional theme park reservation for the second park. If one of the parks has reached capacity for the day, there is a chance you would not be able to park hop, but that is rare, and usually only happens during extremely busy days.
I hope you're able to enjoy the
Lunar New Year celebration of the Year of the Horse taking place at California Adventure during your trip! The
Disney Parks Blog has the foodie guide to browse before your visit, I highly recommend sampling some of the delicious dishes at the festival marketplaces.
Mulan's Lunar New Year Procession is so festive and vibrant, we love to take a break during the day and enjoy this joyous march!
I hope this helps answer your question, Donger! Please come back to planDisney if we can help with anything else!
Have a magical day,
Melissa