I personally have not been to Disneyland but have been to Disney
World several times. Food in the park is expensive. Some ways that
you can save some money is to eat a large breakfast before you go
into the parks, split larger portioned lunch/dinners and share
rather than buying everyone a smaller dinner or lunch, you can also
take in a backpack with some snacks and water.
Check out https://www.mousesavers.com.
It has all kinds of hints and ideas
for making your vaction less expensive. Last time our family went
to DisneyWorld we used the discount codes for rental cars and ended
up getting a great deal!
Good luck and I hope that you have fun! My family loves to go to
Disney, we always have such a good time together.