Solved! Solved! Go to Solution.
No need to apologize for the "noob question", we've all been there at some point.
The reason you're not seeing your theme show up is because of the way that Jekyll handles HTML files. Since you're trying to get your theme to apply to your `index.html` file, you'll need to tell Jekyll explicitly what theme to use for your HTML file.
To do this, delete everything from your HTML file except what's between the `<body`> tags in your repository. Your theme will take care of the other HTML, so you just need to worry about the content of the page, which will always be in the `<body>` of your theme.
Once you've done that, at the very top of your `index.html` file, you'll need to add some Jekyll front matter to select the theme layout your page uses. Since you're using the GitHub Pages "Dinky" theme, you'll want to use the "default" layout.
--- layout: default ---
Once you've added the three lines above to the top of your HTML file, you can commit your changes and your Pages site should start building again. Once it's done being built, you should be all set. You may need to clear your browser's cache to see the changes, but your site should now have a theme applied to it.
Let me know if you have any additional questions!
I was having this same issue and realized that github pages only supports certain themes (https://pages.github.com/themes/), however, you can specify a "remote_name:" in your _config.yml file to use a public theme not listed in the link provided. This post (https://github.blog/2017-11-29-use-any-theme-with-github-pages/) explains further!