Changing link behavior in top menu

I have a site that I am adding the blog to until I can convert the whole thing to WordPress. In the blog installation, I have set up blank pages that mirror the pages of the site so the top navigation is identical to the rest of the site.

Where do I edit to change the links of the nav items so that they link to the pages of the actual site, not to the blank pages living in WordPress?

The site is located at https://www.kleimann.com and the blog at https://www.kleimann.com/wordpress

I am learning PHP on the fly so forgive me if I ask questions that should seem obvious.

Thanks,
Kyle