A book must look right to sell. Even non-readers can tell at a glance that a book does not look right. The Amazon kdp tools are useful but, so far, I have not found an easy way to format it in a way that is indistinguishable from a publishers book.
The answer may be to get a professional to format it. If you are going to do that it makes sense to have the same person create a cover image as a personalised image is a better marketing tool.