How do I display author’s full name in every post?

<?php the_author_meta( first_name, last_name ); ?>

Thanks.

Where do I place this code?

Also, I am not good with codes, is there a plugin for this?

Thanks.

With the help of the Template Hierarchy article, determine what Template is displaying your posts (could be wp-content/themes/your_theme_name_here/index.php). Then edit that and add the code recommended or add

<?php the_author_posts_link() ?>

Related:
Template_Tags/the_author_posts_link
Stepping Into Template Tags
Stepping Into Templates

I am closing this as I have asked a PHP develop to help out.