Welcome to planDisney, Marisa, and thanks so much for your question!
Theme park tickets are usually valid for quite a while before their expiration date - for example, if you purchased theme park tickets today, they wouldn't expire until December 30, 2025.
While I'm not able to see the details of your tickets, the best place for you to check on that expiration date would be in the email confirmation you received when you purchased them. You should be able to find this by searching your inbox for "Disneyland confirmation." The email you'll be looking for will say "Disneyland Confirmation (#DD####....) where the "#" will be a unique ID for your ticket order.
If you scroll down a bit in that email, you should see a header that mentions the expiration date. You'll be able to see the exact date in the section under that header.
Even if your tickets expire before you're able to visit, you'll still be able to
apply the value of those tickets toward the purchase of future tickets that are equal or greater in value as well!
If you're having trouble finding your email confirmation, I'd recommend
reaching out to a Cast Member at the Tickets line. They should be able to help point you in the right direction and provide the information you're looking for.
Thanks again for your question, Marisa! I hope you have an amazing time on your next visit to the Happiest Place on Earth.
Have a Magical Day,
Greg