Trying to add an HTML menu

I have a website already built in HTML that I added a WP blog to:

https://www.prolifeweconf.com

On the site I have placed a navigation menu, formed like this:

<div class="floating-menu">
<h3>Menu</h3>
<a href="#details">Details</a>
<a href="bios.html">Speakers</a>
<a href="artists.html">Performers</a>
<a href="/blog/">Blog</a>
<a href="#Top">Top of Page</a>
</div>

Formatted like this:

<style type="text/css">
div.floating-menu {margin-left: 0px; width: 155px; position:fixed; background:#ddddff; border:1px solid #ccccff; width:150px; z-index:2}
</style>

I want to be able to have such a menu on the blog start page, as well, in order to tie it in better with the site.

My question is, is there a place I can edit the php file to display the menu? I am fairly certain the syntax would have to change — that it just can’t be pasted into a php file this way, but how do I know which file to edit?

The blog is using the 2011 theme, if that makes a difference. I have read everything I can find that addresses customizing the WP site, but either I can’t understand the instructions, or I can’t find the files that are pointed to in the instructions.

Thanks in advance for whatever help you can offer.

Daniel