Greetings, Howie!
Welcome to the Disney Parks Moms Panel. I can't imagine how excited you must be to return back to the Disneyland Resort after so many years. You will love being able to re-live so many experiences you had together while creating new memories that will last a lifetime.
If you only have one day and can only experience one of the two parks at the Disneyland Resort, I would suggest visiting Disneyland Park. Even though you will find many classic attractions that have stood the test of time like Peter Pan's Flight, Mad Tea Party, and "it's a small world" to name just a few, there are many new experiences as well. You can check out the Hatbox Ghost in the Haunted Mansion, meet new Characters, see new sights along the Rivers of America and watch so many new entertainment options. I definitely recommend staying in the park in the evening to watch the incredible
"Remember...Dreams Come True" Fireworks Spectacular. This nighttime spectacular showcases the best of Disneyland Resort - past and present. Disneyland Park is truly the park that started it all, and is the model for every Disney Park in the world, so you really can't go wrong with a visit here.
Although your trip is right around the corner, I would still suggest seeing if you can grab a last-minute dining reservation at a romantic spot like Blue Bayou Restaurant in Disneyland Park or Napa Rose in Disney's Grand Californian Hotel & Spa. I have been very fortunate to get dining reservations at the last minute using the
Disneyland app or by calling the Disneyland Dining Line at (714) 781-3463. It would be the perfect way to celebrate your magical day.
I hope this helps, and have a Fantasmic trip!
-Jennifer