How do I get blog posts to appear within CMS?

So, everything seems to be set up correctly. The setting in your step 2 is everything that needs to be done. I won’t be able to help you without seeing how the theme’s template files are structured.

The way it usually works when you apply the setting in your step 2 is that WordPress looks for a template called front-page.php, if it doesn’t exist then WordPress uses index.php.

Now, one of these templates must use the regular post loop, that is

if ( have_posts() ) :
while ( have_posts() ) :
the_post()

I assume that this loop is not present in your index.php or front-page.php files, and this is why your posts are not showing.