Hey there Marichelo,
Welcome to planDisney and thanks so much for your question!
First off, I have to start with a big HAPPY BIRTHDAY to you! How fun that you get to spend it visiting the Happiest Place on Earth - including the
Oogie Boogie Bash, A Disney Halloween Party.
All of your questions are important, but they're also subjective. So absolutely feel free to disagree with my opinions here and go your own way. However, when I'm planning trips for me and my family and have the Park Hopper option, I like to make sure I have at least one morning in each park and one evening in each park.
I like to have one morning in each park because that's often a great time to get in a bunch of the more popular rides with shorter lines. I like to get one evening in each park because, in my opinion, the parks are most beautiful at night.
Therefore, my suggestion would be to start in Disney California Adventure Park on the 19th and then hop over to Disneyland Park in the evening. Then on the 20th, if I'm understanding correctly, it sounds like you have another park hopper ticket for that day as well? If so, then I'd swap the order and start the morning in Disneyland Park and hop over to Disney California Adventure Park around 3:00 PM for a few more attractions before the party starts.
Since you're visiting during the
Halloween season, I would highly recommend prioritizing all of the seasonal options and entertainment including
Haunted Mansion Holiday and at least two of each of these delicious items from the
Disney Parks Blog Foodie Guide!
I'd suggest also trying to prioritize all the attractions you're interested in prior to your visit to Oogie Boogie Bash. Some people love to enjoy shorter attractions queues during this event, but there is so much to do that is unique to this event like the character meet and greets, treat trails, Madame Leota's Swinging Wake - A Haunted Mansion Street Party, and Villains Grove. Personally, I didn't end up having much time for attractions because I was so busy with all these other experiences!
I hope that was helpful, Marichelo, and that you have a frightfully fun time on your trip next month. Thanks again for stopping by with your question!
Have a Magical Day,
Greg