Hi Teo!
Thank you for bringing your question to the Disney Parks Moms Panel. It's dreadfully delightful to see that you'll be visiting 
Disneyland Resort during Halloween Time!
For 
Oogie Boogie Bash- A Disney Halloween Party, you will find that Disney California Adventure Park will close at 6 PM for Guests that do not have party tickets. If your 
4 day Ticket is for one park per day, you'll definitely want to plan to visit 
Disneyland Park on these days to maximize your time in the park.. If you have a ticket that includes the Park Hopper option, when it's time to leave 
Disney California Adventure Park, you can always just hop across the esplanade to spend your evening at Disneyland Park. For the evenings that do not have a party, you'll definitely want to experience the Nighttime Spectacular available at Disney California Adventure Park, 
World of Color. You can then plan to enjoy Disneyland Parks nighttime offerings like 
Halloween Screams and 
Fantasmic! on Oogie Boogie Bash evenings.
I hope this is helpful in planning your visit to 
The Happiest Place on Earth! Please come back and let us know if we can help in any other way.
-Lindsey