Hello Lourdes,
What I love about park hopping between
Disneyland Park and
Disney California Adventure Park is that the two theme parks are close together and walkable, and yet the experiences are so unique. I'm happy for you to hear that you're wanting to park hop. I always recommend park hopping as a way to make the most of all the magic of the theme parks.
To upgrade the theme park tickets you purchased, you'll want to get the assistance of the Cast Members with the
Disneyland Resort Ticket Services team, as there is not an option within the online ticketing system to upgrade tickets directly. You can call the Ticket Services team at (714) 781-4636 to get assistance with your upgrade.
One quick note I'll offer, Lourdes, is that
theme park tickets are nonrefundable, and so there wouldn't be a way for you to cancel the tickets you already purchased.
One more quick note, Lourdes, is to be sure and make your theme park reservations using the
Theme Park Tickets & Reservations page. There is an option you'll see for making theme park reservations for Guests who have already purchased theme park tickets.
Lourdes, here's wishing you all the fun enjoying both Disneyland Park and Disney California Adventure Park!
Jerry