Create and Assign Role to User

Here is the example of creating new user and insert in to users table with wp_create_user function as well also with wp_insert_user function

    $username = 'username123';
    $email = 'drew@example.com';
    $password = 'pasword123';

    $user_id = username_exists($username); //Check Username is exist
    if (!$user_id && email_exists($email) == false) {
        $user_id = wp_create_user($username, $password, $email); // It Will Create User
        if (!is_wp_error($user_id)) {
            $user = get_user_by('id', $user_id);
            $user->remove_role( 'subscriber' ); // Remove Role 
            $user->set_role('editor'); // Set Role 
        }
    } else {
        echo( "Error: " . $user_id->get_error_message() );
        exit;
}

//Same can be done with wp_insert_user function

$userData = array(
            'user_login' => 'username',
            'first_name' => 'First',
            'last_name' => 'Last',
            'user_pass' => 'password',
            'user_email' => 'you@mail.com',
            'user_url' => '',
            'role' => 'administrator'
        );
wp_insert_user( $userData );