If you don't get a reservation for a restaurant you want to try, just go up to the host/hostess and see about being put on the wait list. For example, if you want to have lunch at Carnation Café, get there at 11:30 or preferably earlier and let them know you want to get on the wait list. They usually have a person outside around this time. They will take your cell number and send you a text when your table is ready. It will be about a 30-45 minute wait. I know you can do this at most locations that require reservations.
Regarding the beignets, I say don't waste your time on the ones at Disneyland. At least that is my opinion. The best ones on property are at Jazz Kitchen Express in Downtown Disney. Along with their regular ones, they always have a limited time flavor. Currently it is Snickerdoodle. If you happen to be at DLR when they have their Mardi Grad flavored one, I highly recommend them. For the best ones in the area, you have to cross the street to Anaheim GardenWalk and go to Huckleberries. They have the best beignets. They are only open for breakfast and lunch which I also recommend. I have tried 5 different items on their breakfast and lunch menus and they have all been delicious.