Hi Amanda, welcome to planDisney!
Good news is that theme park reservation availability is constantly changing, as Guests can revise their reservations as they see fit! I recommend you keep an eye on the
Theme Park Reservation Availability Calendar, as it will show you if reservations become available for sold out days. Also, you'll notice that there is different availability for one park per day tickets and park hopper tickets. I recommend you keep an eye on both. I just took a peek, and looks like the one park per day tickets have availability for both
Disneyland Park and
Disney California Adventure Park! I think that's the day you’re interested in right? Hopefully, the one park per day tickets work for you!
And you chose a great time to visit! As you might already know,
Halloween Time at the Disneyland Resort has kicked off and will last through October 31, 2022! I personally love the Halloween overlays that you can experience, such as the
Haunted Mansion Holiday at Disneyland Park, where Pumpkin King Jack Skellington has been busy decorating with frightfully festive touches, and
Luigi's Honkin' Haul-O-Ween and
Mater's Graveyard JamBOOree at Disney California Adventure Park, which is great for little kiddos!
See ya real soon!
Jin