The meta box is called “Page attributes” and is displayed under the one called “Publish” (which has the Status, Move to Trash, publish date, etc), in the right side.
The Page attributes meta box also has the “parent” select box. If you don’t see it there, click on Screen Options (top-right) and check “Page Attributes” check-box and it will show up. Hopefully :). If you still don’t see it, there are 2 cases:
1. Your WP installation is corrupted and you should try a re-install from the updates in dashboard.
2. You’re using a plugin that hides parts of the WP dashboard and you have accidentally and/or mistakenly hidden Page Attributes (in which case solution number 1 won’t work, you need to unhide Page Attributes from your plugin).
Another possible cause you’re not seeing the template is if you have altered the header (the commented) part from it’s beginning. WP uses that comment to classify it as a template. I’m talking about:
<?php
/*
* Template Name: Blog Posts
* @package Customizr
* @since Customizr 3.0.12
*/
?>
This should start from first line of the file and remain untouched.
That’s about it.