Issue moving subdirectory to root

Thanks in advance. I’m new here, but I couldn’t have learned all I have so far without all of your help.

I had built https://www.johncolvert.com/wordpress. It looked and worked exactly how I wanted it. Ready to move it over to the root folder (www.johncolvert.com), I followed this video perfectly (to my knowledge) and then once I reloaded the site, it was ruined… no widgets, background image, header, etc. So, panicking I reversed my steps to put it back into the sub-directory. Everything moved back, but it still looks as it did when I first moved it to the root.

I’m assuming (and hoping) it’s a simple fix. I’ve been on the forums for hours and have gotten nowhere… please help! Thanks.