You simply need to add the code to your theme template.
For example:
$value = get_field( 'my_field' );
if($value):
echo $value;
endif;
Just change my_field to the name of your custom field.
Depending on your theme or where you want the code, you may need to use:
$value = get_field( 'my_field', $post_id );
Maybe share your code and we can see what you have and help a little more.
