Friends Page
The Friends plugin adds a page to your site that can be accessed under the URL /friends/
Any visitor (and search engine) can visit this page. To see this page you can use the Incognito Mode of your browser, or you can access it via the menu "Friends → My Public Friends Profile".
You can edit this page, since it is a regular WordPress page. The easiest way is to click the "Edit Page" link in the Masterbar on the top of the page:
When logged-in, the /friends/ URL will show your personal Feeds, something like this:
You'll notice that this has a different design, independent of your theme. This decision was made because of the huge variety of themes that would otherwise interfere with that structure.
It is possible to modify this UI using additional plugins, you can find out how it can be done in the developer documentation for overriding the templates.