Adding custom site header and footer

Hi! I’m pretty competent in HTML, but only know a tiny little bit of PHP. I really like the WordPress software and have seen quite a few sites where it is incorporated really well within the site.

Here’s what’s up. I am using the Unicorn theme (a child theme of Jolene): https://www.trumpipedia.com/blog. Customization seems to be going pretty good. But I have a header and footer (via SSI) on each and every page on the site. For example, https://www.trumpipedia.com/resources/glossary.

I would REALLY like to be able to incorporate my site’s header and footer into the blog. That way the blog appears in between the header and footer, and the blog looks like is in integrated within my site.

I have been through a TON of threads here… spent the last several hours reading posts and trying to incorporate them but it’s no use. Right now I have the site header here: https://www.trumpipedia.com/includes/header.htm and the footer here: https://www.trumpipedia.com/includes/footer.htm.

All I need is to be able to add the header to the top of the page and the footer to the bottom. They everything would be PERFECT! Can ANYBODY help!? Thanks!