Hello there Susan, and welcome to planDisney!
I love that you're thinking about upgrading your
theme park ticket to a
Park Hopper ticket. Since it is so convenient to park hop at the
Disneyland Resort and walk across the Esplanade to the other theme park, I always recommend it!
Good news Susan, you can upgrade your ticket by visiting the ticket booths at the Disneyland Resort near the main entrance. However, if you want to investigate options before your trip, I recommend
contacting the Tickets phone line to speak to a Cast Member for assistance.
If you're only visiting the parks for a day or two, I highly recommend purchasing
Disney Genie+ Service. Disney Genie+ Service will give you access to
Lightning Lane entrances, and will help save time with access to shorter wait times. It's a must for us every visit, and if you do have a Park Hopper ticket, you are able to use Disney Genie+ Service at both parks after you're able to hop to the other park! We've been in
Disneyland Park having a great time, and then book a Lightning Lane for
Incredicoaster over in
Disney California Adventure Park since it's such a short walk over to the other park.
I hope this ticket information was helpful for your upcoming trip Susan, and feel free to
come back and ask me any other questions as you plan for your vacation!
Have a magical day!
Melissa