Aloha Alden! Thanks for visiting planDisney.
You can
purchase admission tickets online directly from Disneyland Resort. You'll be asked to select your preferred day and park subject to availability. This is your theme park reservation, which is required along with a valid ticket for entry to the parks at this time. Prices and terms are subject to change. When you pick the
Park Hopper option, you choose the park you'd like to start the day in. You can check
availability before you purchase, which is handy. Hopefully, your perfect day is still available.
You'll be able to hop to the other park later in the day. It gives you a lot of flexibility in your plan for the day! We love the Park Hopper option as a family. We often start our day in one park, have lunch, and then hop over to the next park for more Attractions and Entertainment. We'll hop back to the starting park too. You can do that.
Another great option is
Disney's Genie+, which lets you spend less time in queues and more focused on the magic of your day. If you don't select this option at the time of purchase, you'll have the option to add it after scanning into the parks. You should see the button to purchase toward the top of the Disneyland mobile app. The daily price might not be the same as the pre-purchase price. Genie+ can sell out for the day, so arriving early will give you more time to enjoy the parks as well as a greater chance to select this option prior to it filling up.
Have a magical day!
Elizabeth