How to show all CPT posts in one page?

I think you can do this if you think through how the template hierarchy works carefully enough.

• archive-post.php should handle your standard post post types
• archive.php would then handle the rest of the archives
• You may want specialized category– category.php
• or tag archives– tag.php

A similar pattern should work for single post display.

• single-post.php should handle your single post post type
• single.php should handle everything else