Hey there, Diego! Thanks for coming to planDisney with your question. Planning a trip to the Happiest Place on Earth is one of my favorite things to do!
Diego, while
tickets are available at the main entrance ticket booth once you arrive, it will be subject to availability of
park reservations, as each Guest will need both a valid ticket and park reservation. The Cast Members at the ticket booth access the same
online reservation system that Guests access from home on the
Disneyland website. As of now I don’t see October 13 available, however, sometimes reservation availability can change at the last minute as other Guests change plans and cancel reservations. I would keep checking just in case you get lucky!
Just for future reference, reservations can be made up to 120 days in advance. I know sometimes an impromptu trip to the parks is what we need! But if you have the ability to plan ahead, I wanted to share the timeframe within which reservations can be secured.
Wishing you the best of luck to secure those tickets and reservations!
Kamini