Hi! For what I know (but I’m no expert), you basically need to “tell” your site exactly where you want the feed, as it is of course better that the site doesn’t choose by itself (a feed that would appear anywhere on your site just by activating it would be out of your control).
If you want it in a page or post, go to the respective section in your WordPress dashboard and open that page or post and paste the code there.
If you want it in a page that’s not encoded as a page by WordPress (that is, the pages that are created in the homonymous section of your dashboard), like for example an archive page created with a php file in your editor, then use the widget function of the plugin (if you’ve installed the plugin, you will find its widget in the Widgets section of your dashboard, under “Appearance”). Only, in this case, you’ll have to “summon” the widget in the php file with CSS code, and that’s definitely out of my reach to teach you.