I take it you have some sort of navigation section with the features listed. The question is how that navigation is implemented.
If it only appears on one page, you'd probably just have to add to that page. But usually the navigation stuff appears on multiple pages, so the next question is how it's implemented. Check the file extensions: if the page names end in .htm or .html, then each page probably has a separate copy of the navigation and you'd need to edit it in each page's source code.
If you don't have the source code, download a full copy of it to your own computer and keep a development copy there from now on. I have a "Websites" folder with subfolders for each site I maintain, plus a few I've never actually deployed but have played with. You should have a backup copy of everything on your website, including all the subfolders with images and such. Bluehost has an "unlimited FTP" utility that's good for large-scale copying onto or off the website; you need to be a bit careful about whether a file is text (.htm, .html, .css, .js, .php) or binary (.gif, .jpg, .doc) to make sure it transfers correctly.
If your pages are PHP (.php), which Bluehost does support, it's dollars to donuts that your navigation is contained in some accessory PHP file and incorporated on each page by calling it. How that's done depends on the programmer; my pages that do this have code in them, among the HTML, that looks like this:
require 'navbar.php';
navgen('documnts.php');
?>
The file that's named in the "require" call contains my navigation code; the navgen() function is called to run the code. If it's PHP, you might need to learn the language or find someone who knows it to help. Also, unless you've got server code with PHP support installed on your own computer, you won't be able to test PHP modifications there; you'll have to try them out on the website itself. (If you don't know exactly what you're doing with the language, that's obviously a bit risky; you should keep an unmodified copy handy to replace your new version with if it appears to have any problems.)
Next day:
Dropped in to check on the status of this. It sounds likely that the navigation is encoded in PHP. (It occurred to me that it might also be generated in JavaScript, but if the whole site is PHP, that's unlikely.) You probably would be best off getting a PHP programmer to work on it
Your best method of posting your website here is simply to go to its home page and then copy the address from your browser's Address field and paste it in here. We might be able to pull enough source to figure out what file generates the navigation entries. But it's best maintained by someone who (a) knows what they're doing and (b) has a copy of all the code on the site, and that's more work than you should ask to be done by respondents here.
You could also learn (a) HTML, (b) CSS, and (c) PHP yourself. That's not as hard as it sounds.