You don’t need to publish with Amazon to play with their creative cover design tools to begin imagining what your published book could look like. All you need to get started, is to sign up for an amazon account, if you don’t already have one and go to amazon.kdp.com and follow the simple steps to creating an ebook. You just come up with a title (but you can change this at any time); fill in your name as the author and then just begin being creative. You never have to actually publish it – just play and get ideas on KDP (kindle direct publishing) and then find a high quality equivalent type image that you really like (300 dpi and as large as possible for under 10 dollars – that will be good enough to produce a physical book cover), from canstock.com for example, where you can directly download it and it is yours – no licence, no royalities, no subscriptions etc. Below is a great little video to show you how to create covers on kdp.