Hey there Abby,
Welcome to planDisney and thanks so much for your question! It sounds like you're headed to
Oogie Boogie Bash - A Disney Halloween Party - how fun! I was able to attend with my son in September and we had such a fun time!
According to the
Disneyland Resort Dress Code FAQ, masks of any kind may not be worn for Guests ages 14 and older during Oogie Boogie Bash - A Disney Halloween Party. It's because of this rule that I recommend not trying to bring a mask with you so that you don't get turned away at the gate.
The event starts promptly at 6:00 PM, but with your special event ticket, you can enter Disney California Adventure Park as early as 3:00 PM. It definitely felt more crowded in the hour before the event as there were both event and non-event Guests in the park. My recommendation would be to arrive at least by 5:00 PM so you can be ready and in the park as soon as the event starts as opposed to still waiting in line to enter.
All of the
treat trail lines that we waited in moved pretty quickly - even the ones that looked very long. It was the character experiences lines that seemed to take the longest, so if there were a few characters in particular that you wanted to meet, you might want to prioritize them first.
You're going to have so much fun, Abby! Thanks again for your question. Come back and see us here at planDisney if you think of any follow-ups. We'd love to help!
Have a Magical Day,
Greg