Hi Liza, welcome to planDisney!
Excellent decision on purchasing the
Park Hopper Tickets! My family and I are huge fans of the park hopper tickets. Being able to "hop" between the parks really allows you to maximize your schedule. Two thumbs up!
Now on to your main question, you CAN change your starting theme park, BUT to do so, you have to actually cancel your current
theme park reservation for
Disney California Adventure Park, and book a new reservation for
Disneyland Park. Also, you have to check the
Theme Park Reservation Availability Calendar to see if Disneyland Park has reservation availability. But before you attempt this, please understand that even if Disneyland Park has availability, there is always a chance that the reservation will get booked during the few minutes where you are canceling your current reservation and trying to book a new one. Guests have informed us of this happening, so there is a risk. With your magical trip to the
Disneyland Resort just around the corner, I personally would not take the risk of losing your current reservation!
Also, I wanted to quickly check to see if you've already purchased the
Disney Genie+ service? If not, I highly recommend it! My family and I just came back from a trip to the Disneyland Resort, and we utilized Genie+ throughout our trip. We found it to be a game-changer, as we were able to avoid the standby lines, and access the
Lightning Lane entrances for many attractions! If you haven't purchased Genie+ yet, you'll need to wait until you've entered one of the theme parks, and then move forward with the purchase in the
Disneyland Mobile App.
I hope you have the most magical time on your trip!
See ya real soon!
Jin