Should you have titles for the chapters in your book? Some writers do it and some don’t, and arguably, some stories are better suited to them than others. The trick is thinking of a name that identifies the key event of the chapter without giving too much away! Also, you have to beware of clichés—I personally have a bad habit of thinking up names like those in the Famous Five novels. Also, it’s sometimes quite hard to think up a good name, especially if the chapter is short and is character-centric.
Try to think of what is happening in the chapter from a birds-eye point of view, and especially what is happening in the middle point of the chapter or just before the chapter ends. This part of the chapter is a good candidate for picking a title. You can’t pick a title based on what’s happening at the end of the chapter because that would give your story away (which is a no-no, of course). Now, all this is assuming that your chapters end on a cliffhanger or soft landing (I called this a ‘bouncy cushion’ once).
If an unexpected event occurs during the chapter then you might want to think about whether the title should hint at this or not. Perhaps you could arrange the chapters so that the unexpected event happens at the end of the last chapter, so that the title of the new chapter can reflect the consequences of the event rather than the event itself.
Now you may wonder whether it’s worth having chapter titles at all. It’s all up to you, but it looks like many children’s novels do have these titles. Novels for older readers sometimes do have them. Some writers also like to include quotations or symbols for each chapter, as might be relevant to the story.