Drupal 8 user insert give default role

hook.module

/*
*  Impliment user insert give default role.
*/

function hook_user_insert(Drupal\Core\Entity\EntityInterface $entity) { 	
  	$entity->addRole('role_name'); 
  	$entity->save();
}

hook1.module

<?php
/*
*  Impliment to give customer default role
*/
function hook_user_insert(Drupal\Core\Entity\EntityInterface $entity) { 	

  	$connection = \Drupal::database();
	$query = $connection->select('users_field_data', 'u');
	$query->condition('u.uid', 0, '<>');
	$query->fields('u', ['uid']);
	$query->join('user__roles', 'r', 'u.uid = r.entity_id');
	$query->condition('u.status', 1);
	$query->condition('r.roles_target_id', 'consultant');
	$result = $query->execute()->fetchAll();

	$query1 = $connection->select('user__field_consultant', 'c');
	$query1->fields('c', ['field_consultant_target_id']);
	$query1->range(0,1);
	$query1->orderBy('c.entity_id', 'DESC');
	$result1 = $query1->execute()->fetchAll();

	$second_last = 0;
	if (isset($result1) && isset($result1[0]) && isset($result1[0]->field_consultant_target_id) && ($result1[0]->field_consultant_target_id > 0)){
		$second_last = $result1[0]->field_consultant_target_id;		
	}

	$user_list = [];
	$count = 0;
	$last = 0;
	foreach ($result as $key => $consultant_user) {
		$user_list[$consultant_user->uid]  = $consultant_user->uid;	
		if($count == 0){
			$last = $consultant_user->uid;
			$count = 1;
		}
		if($second_last == $consultant_user->uid){
			$count = 0;
		}
	}

  	$entity->addRole('customer'); 
	$entity->field_consultant[] = ['target_id' => $last];
  	$entity->save();
}