// hook when user logs in
add_action(\'wp_login\', \'your_function\', 10, 2);

function your_function($user_login, $user) {

    $user_id = $user->ID;
    // getting prev. saved meta
    $first_login = get_user_meta($user_id, \'points\', true);
    // if first time login
    if( $first_login == \'1\' ) {
        // update meta after first login
        update_user_meta($user_id, \'points\', \'1000\');
        // redirect to given URL
        wp_redirect( \'http://levangiang.net/\' );
        exit;
    }
}