I am pretty new to WordPress and ACF so please bear with me )
I have created a custom, theme with some templates.
In the admin I have used ACF to create some custom field e.g. left_text and right_text, and I have set the value for those fields in a post I created.
Then in the template I use <!-- wp:acf/left_text --> but it does not output the value for left_text any ideas what am I doing wrong?
the tags you are referencing are processed by WP when it gets the content from the WP editor. I have no idea how these tags are processed in the PHP template or how to include acf fields in this manor.