Trying to change theme to look more like existing site.

I’m working on adding a blog to an existing site. I only need it on the main index page of the site but I’d like to make it look more like the rest of the pages on the site. I’m using Majestic from https://www.freewpthemes.net/ as my overall template and have gotten it close to what I need. However I need to change the header so it has the skull logo and banner that the other pages use. When I try to insert them into the header.php file the alignment of everything goes wonky. Also I want to use a text widget to create the vertical nav bar on the left side but when I use the same code that does it on the rest of the site the buttons get cut off.

https://www.voxmortuum.net/ The main page of the site with the blog.
https://www.voxmortuum.net/crochet/c_original.htm One of the inner pages with the graphics visible I’d like to use.

Any information would be greatly appreciated. I’m not unfamiliar to code but I’ve been working on this so long I’m not seeing what’s wrong.