inserting theme into existing website, formatting error in post content section

I created a very basic wordpress theme on another URL, and the layout, formatting, and all is working well.

I wanted to install a the same theme within my personal website. So far so good, however, the postcontent does not seem to be formatting correctly: https://www.haleywiley.com/blog. The text within the post is stretched. Bullets also appeared, but I was able to remove those (these were not on the original theme). I’ve tried different things in the css. It seems nothing should have changed much from the theme which was working fine on the original URL. Transitioning this theme into another div column on this site has proven difficult, but I’m almost there. It seems it’s picking up a page width somewhere, but adjusted it, with no change.

Appreciate the help. Thank you in advance!