My sims don't get pizza if they burned a meal. Instead, they try again. But when I'm first starting out with a new sim, I almost always have them start with autumn salad for their first meal. Then they can eat leftovers of that if they burn subsequent meals, even for breakfast. By the time the leftovers are gone, they are high enough in cooking skill that they don't burn food anymore. Since every bookcase comes with a cooking skill book, they can read that if they need to, to get their skill up. If they don't have a bookcase, I'll send them to the library to read the book.