Project
When creating a new content type, there are a few things to configure.
I often deselect promoted to front page, create new revision, display author and date, and available menu.
Image

To do this, I added a form alter in mantratheme.profile.
Set the default values we want in #default_value.
The tricky part is knowing what format to use. The multivalue options are in an array, but the display submitted is just a boolean. Use a debugger to see what values are currently in use.
/**
* Default settings for new content types.
*
* Implements hook_form_FORM_ID_alter().
*/
function mantraprofile_form_node_type_add_form_alter(
&$form, Drupal\Core\Form\FormStateInterface $form_state)
{
// Unset publish to front, create revision.
$form['workflow']['options']['#default_value'] = ['status'];
// Unset display author and date.
$form['display']['display_submitted']['#default_value'] = 0;
// Unset main menu.
$form['menu']['menu_options']['#default_value'] = [0];
}