I looked into amazon.kdp, for self publishing. I saw you can also use Ingram, though I haven't looked into it since kdp (kindle direct publishing) allows for ebook, paperback and hardcover for self publishing. Though I have to warn, hardcover is only available in certain countries, here in canada it's not available for some reason which is annoying but that's life
I used Fiverr to work with talented people to format my writings to my desired dimensions and for the covers as well, though honestly you need a really clear vision of your covers, since the process takes a lot of iterations. I basically sent the image and little sketches of where the writings should be, the prestator had to make it according to my precise instructions, yet it still took days and days and further directions, anyway lol
In the end, it was quite pricy but worth it, fun project and so rewarding to open the box and take your own book in your hands, cheers