Custom Post Fields / Meta boxes

Hello there, I am trying to figure out how to disply the info from custom fileds in a post. I have read the /Function_Reference/get_post_meta tut and codex several times but I am still not getting my fields to display. I have a few custom fields that I built using this tutorial https://www.wpbeginner.com/wp-tutorials/how-to-add-custom-meta-boxes-in-wordpress-posts-and-post-types but when I try to display them, they simply come up blank. So, with the /Function_Reference/get_post_meta
I just dont understand if I am supposed to literally put <?php $meta_values = get_post_meta($post_id, $key, $single); ?>
or do i need to change something to reflect the post id or the key, or whatever, it seems that wordpress codex does not go so far as to simply say, ok change the key to your name of the filed and change post id to something, its very cryptic at best, so can anyone help me with this please?
Also, please do not close this thread until I get a resolve like you guys do with so many unanswered questions. Thanks.