Where do I need to put this code for related posts plugin?

I uploaded the wordpress related posts plugin and it tells me to – “Place <?php wp_related_posts(); ?> in your templates” I don’t know where that is or how to do that. Can you please tell me where I should place this code so that the plugin will work?

Thanks!

Or, is there a different ‘related posts’ plugin that is better (for someone with limited code knowledge)

Thanks much!