The title is the first piece of information someone gets about your book, and it often forms the reader’s judgment about your book. A good title won’t make your book do well. But a bad title will almost certainly prevent it from doing well.
A good title should be attention grabbing, memorable, informative, and easy to say. Spend a few days writing down every single title idea you can think of. You can use clever or noteworthy phrases from the book, metaphors or symbols associated with the themes in your book, as well as relevant keywords. It should pique the reader’s curiosity, without giving away any spoilers. If you’re stuck, you can try Random Title Generators, or do a quick search of best book titles as a source of inspiration.