You should have an XML sitemap on your site for search engines. Usually it’ll be at [your domain]/sitemap.xml, although that might redirect to something like sitemap_index.xml. It’s probably created and updated by your content management system.
But what about a sitemap for website users? This is sometimes known as an ‘HTML sitemap’ and is a list of all the pages on the site. It can be useful for some visitors, especially those who like to use the ‘search’ facility in their browser and just want a big, all-pages-at-a-glance index to search. It also outlines the site’s structure and scope, which can be useful for many reasons.
Here’s one we have for the blog posts on our (admittedly very simple) site. You might like to consider the same, but remember that as it’s aimed at human users, you should link to it in the site navigation!