How would I go about coding a generic tag.php page that displays all the posts with a specific tag?
For example, if I navigate to example.com/tag/your-tag, it should display all posts with the tag "your tag".
Create tag.php & save it in your theme directory. This is a default behavior of wordpress. So you don't have to struggle with it.
<?php if ( have_posts() ) : // Start the Loop. while ( have_posts() ) : the_post(); // Do your stuff here such as below the_title(); the_content(); endwhile; else: echo 'No Post Found'; endif; ?>