The Gray Whale is beautiful!

Its exactly the style that I have been looking for. I just downloaded it today and have been working on getting some pictures up but am having some issues. I am squeaky new newbie to using WP so not sure if operator error or what.

The images I loaded into the header do not randomize. However, now there are no images showing up. The home page is all gray, no image.

I have gone through several themes in the past few weeks looking for the right one and I know I found it in Gray Whale, but I am such a non-techie newbie I a not sure how to fix this. Would it be better to remove then reload? The content I have on it has been through many iterations and themes. I like this one ALOT! but am at a loss.

I will continue to tinker but I hope someone can get back to me soon. The website is
https://www.urbangardennatives.com