When editing any If-So condition, select CRM Tags (any) from the Select A Condition dropdown.
You can then select one or more CRM tags in the Select Tag(s) box, and add your content.
The content will then only be displayed to users who are logged in and have at least one of the specified tags.
When editing any block in the block editor, select User has tag as a condition from the If-So conditions panel, and select a tag.
The block will only be shown if the user is logged in and has the specified tag.