Hello again Kirsten,
Please don't feel like your question is silly - we are here to help!
Tickets are available for purchase from sales locations every day at each of the theme parks. You can also pre-purchase your tickets
HERE for collection at the will call windows starting the day after your order. (If using this method, you will be required to present your confirmation and a valid photo ID)
The sales locations are situated before you reach the turnstiles where you must insert your ticket to gain access to the park itself. They are usually most crowded just prior to park opening so I would suggest getting there a little early or slightly after the park has opened to minimise your wait in line.
The parks have been known to stop guests from entering due to reaching capacity however, you will be glad to hear that this is only during extremely busy times of year such as Christmas day. I cannot see any reason why you would have any problem with gaining access to any of the parks during your stay.
Wishing you a truly magical holiday!