Full post/comment page not showing up…

I got most of my custom wordpress theme to work, except for when I click to see a full post/comment page, it doesn’t show up. Here’s the first page https://thesunnydalecrypt.stangerdesigns.com/…but when I click the title of the post to go to the page that would allow me to comment, nothing shows up. Does anyone know why? Also what are the key pages that need to be edited for a custom theme?

Thanks