Guten Tag, Gerald. Welcome (Willkommen) to planDisney and thank you for bringing this question to us. It's always a good idea and I fully support adding an extra day of magic to your upcoming visit to the Disneyland Resort.
One of the great things about Disneyland Resort theme park tickets is that there is some flexibility built into them. The good news is that you can
upgrade your 2-day theme park ticket to add another day as long as the cost of the new ticket is equal to or greater than the price of your original ticket.
So let's get to the part about how to make this magic happen. It's recommended to make any changes and upgrades in person at the ticket booths at the main entrance, however, that could get tricky with the need to make park reservations. I would suggest
calling a Cast Member that can assist with Tickets to see if they are able to help with your request over the phone to allow you to secure your theme park reservations before you arrive.
Once you are all set with your tickets, you might want to think about making reservations for any table-service dining that you might be interested in.
Advance dining reservations can be made up to 60 days in advance of the day of your visit. A couple of my favorite places are Lamplight Lounge in Disney California Adventure and Carnation Cafe in Disneyland Park (the fried pickles are amazing).
It's a wonderful time to visit the Happiest Place on Earth. The
Disney100 Celebration is in full swing and there's no shortage of magical things to see and do to fill up all three of your days. When you arrive, I recommend downloading the
Disneyland app. It's a wonderful and helpful tool with a map of the entire resort, attraction wait times and much more. One of my favorite features is the Mobile Food & Beverage Ordering - I've found it to be a huge time saver. There's also a handy guide to the Disney100 Celebration festivities on the home screen of the app. Make sure to catch at least one of the new nighttime spectaculars.
I hope this information has been helpful to you, Gerald. As you continue to plan, please come back and ask us any other questions that come to mind. Here's wishing you a most magical visit.
Michelle