Greetings to you, Gabriel, and welcome to planDisney!
Thanks for submitting your question to us and congratulations on scheduling your very first trip to the Disneyland Resort! I'm really excited for you! What better way than to visit the Park that started it all way back in 1955? There's definitely a sense of pride in calling this my home Park because Walt Disney himself walked these pathways and had a direct hand in many of the attractions that are still there to this day.
Your question sent me down quite a rabbit hole, Gabriel! I'm not associated with any military or law enforcement branch but I have the utmost respect for their members. I've witnessed a challenge coin trade while visiting the Walt Disney World Resort but have not yet seen any at the Disneyland Resort. That doesn't mean they don't happen, however. Disney Challenge Coins (both officially sanctioned by Disney and custom made coins) are out there and the most likely Cast Members who would be willing to trade would be the Security Managers. You can always ask and the worst that can happen if you inquire about trading challenge coins would be that they say no.
If you're into collecting coins, one thing I might recommend would be to look at the
Collectible Medallion Machines that are spread all throughout the Disneyland Resort. They even sell a Collectible Medallion Souvenir Book in which to store them all.
Otherwise, I hope you're all set for your trip! Make sure that you have your
Theme Park Ticket and park reservation all ready to go. Have you downloaded the
Disneyland Mobile App to your phone yet? It will come in very handy. Disney also provides various
Services for Guests with Mobility Disabilities which you might find useful. When you're there, you'll see an interesting mix of Halloween Time and the Holidays as the decorations are being transitioned over. But it's still a super festive time and I know that you'll have a wonderful trip!
Gabriel, thanks again for stopping by and I wish you a magical trip to The Happiest Place on Earth! Please don't be a stranger and feel free to write again if you have more questions. We're always happy to help.
Wishing You a Great, Big, Beautiful Tomorrow!
-Al