Hello Delara! Thank you for visiting planDisney with your great question. How exciting that this will be your family's first visit to the "Happiest Place on Earth!"
We usually spend more days in
Disneyland Park during our trips since it is much bigger and there are more attractions to experience, but we absolutely love
Disney California Adventure Park. I think splitting it up with three days in Disneyland Park and two days in Disney California Adventure sounds perfect so you have enough time to experience everything both parks have to offer. I also love to alternate days in each park like you mention, and you can make your
theme park reservations accordingly, that sounds like the perfect schedule.
We love the Marvel movies and characters, so we love to spend a few days in Disney California Adventure Park to make sure we experience
Avengers Campus as well as ride the
Guardians of the Galaxy - Mission: BREAKOUT! attraction, it's such a party from start to finish. If you have
Star Wars fans in your family, you have to experience
Star Wars Galaxy's Edge in Disneyland Park, and all of the characters, attractions, food, and specialty shops it has to offer.
Don't forget to pickup a complimentary "First Visit" celebratory button either at City Hall on Main Street, U.S.A. in Disneyland Park, or you can ask many of the shops throughout the parks. If you wear them proudly throughout your trip, you'll usually get a ton of special shoutouts from both Cast Members and Guests!
I hope you and your family have the most magical first trip, Delara! If you think of any other questions we can help with,
please come back and ask, we are here for you!
Have a magical day,
Melissa