Hi, Jun Ho! Welcome to planDisney and thanks for your question!
In order to visit the Disneyland Resort, all guests must have a valid theme park ticket and a
theme park reservation for each day they want to visit. So, if you haven't already made your theme park reservations, you will want to do so before making plans to visit the parks. You can check the
theme park reservation availability calendar to see which dates are currently open for reservations.
If you are looking to visit this month, there is very little availability left. It's always possible that more availability could be added as time goes on, so definitely keep checking back to see if anything opens up. Otherwise, your best bet would be to make a reservation for January or later. If you purchased your tickets this year, it is very likely that are valid all the way through 2023. So you can always hold on to them and wait to plan a trip sometime in the future.
I hope this helps. Have a great day!
-Linda