Hi there Margherita,
You're going to love Halloween Time at Disneyland Park with Mickey's Halloween Party! As Scar from The Lion King sings, "be prepared" to see Disney villains throughout the evening. You'll have the opportunity to Trick or Treat in Disneyland Park, enjoy the ghoulish "Halloween Screams" fireworks, and of course enjoy the holiday attraction overlay of The Haunted Mansion and Space Mountain.
Kids of all ages may dress in costume for Mickey's Halloween Party,
here are the details. Your family can dress in a costume of their choice as long as they are child-friendly. Last year we saw an entire family in a Mario Brothers theme, it was adorable. Remember, you may enter Disneyland Park three hours before the party starts using your Mickey's Halloween Party ticket.
I hope this helps and that you all have a Boo-tastic time. If you have any more questions, please feel free to ask me, I'm here to help you plan your magical vacation!
Wishing you 999 Happy Haunts!
~ Lynette