Blog issues on "That Music" theme

Posted this in “Themes” but no responses — can anyone help out here?

Hi — I’m using “That Music” theme and have been unable to figure out a problem. I set my blog posts to post on a static page I created called “blog”. https://www.bandpromo.me/blog

I have the Dynamic Headers by Nicasio Design plugin and the PixoPoint Menu Plugins enabled. I’m trying not to display the large image on the blog page using the plug-in but it is displaying anyway. I also have a custom nav bar enabled, but I’m getting a strange remnant of the original navbar showing underneath.

Any idea what theme page I can customize to make the changes above? (and what the changes need to be?). I’ve been poking around different pages but can’t figure it out. Thanks!