Yeah, KDP is a very easy way to get ebooks onto Amazon. That’s how I’ve done things there in the past. You can sell on KDP and still make versions (even free versions) available elsewhere (such as your website); it just would bar you from also signing up that book to the KDP Select side of the service.
(Was certainly much easier than doing stuff on the Kindle than the equivalent Apple side of things. Mind you, I went through so many self-publishing hoops in the past; such as bulk buying ISBNs, phoning up the US tax office from overseas, etc. that I forget how more difficult things were a decade or so ago.)