Now I read something different. I read the you could not bring in any food. In the past they didn't want you to bring in food but most of the time didn't say anything. I don't know what they will do now. They do search anything you bring into Disneyland or California Adventure but I don't know if they will pull out snacks. Since you will be staying there you will probably go in a different way so maybe they will not look. I am going to California Adventure on Sat. and I will put a few snacks in my bag and will let you know if they say anything.
As for eating at the park a friend of mine stayed there and said they found it cheaper to eat in the park then at Downtown Disney. You could also walk across the street from Disneyland at night for dinner. I think the is a Dennys and a McDonalds. There are a lot of other places but I can't remember what. Also in the park there is a saloon in Frontier Land. They have shows by Billy Hill and the Hillbillys. It is great fun and even my 12 and 13 year olds like it. They serve food and dessert. We usually get a couple desserts to share and enjoy the show. You can watch the show even if you don't buy anything. Around the corner from the saloon is a place that sells hot dogs. I think it may be the cheapest place to eat at Disneyland. We also go to a place the sells hambergers and a couple other things by Splash Mountain. The hambergers are a good size and you get a lot of fries. Its about $10 per person but is a good price at Disneyland. I think it is called something like Country Bear Cafe.