Output the label of an ACF field
You can output the label of an Advanced Custom Field: ACF field by using the get_field_object() function which stores an array of data about the custom field.
/*
* Output Label from ACF field
*/
$field_name = "acf_field_name_here";
$field = get_field_object($field_name);
echo '<h3>'. $field['label'] . '</h3>';