Incoportaing wordpress into a Main frame site

This has probably been asked over and over, but I want to incorporate the blog in the main frame of the site..see https://www.intelligenceinateacup.com the wordpress URL is https://www.intelligenceinateacup.com/wordpress do I have to change the external theme in the theme editor and then place by dream weaver html code into this..whenever I try to do it, it makes it appear awful, just goes all over the place. Basically I want it like Steve Pavlina’s site, which the article is posted into his custom made site framework. Or do i just set up a relay, so it just relays the article into that space?

Cheers in advance!