merolhack

Drupal 8 is really beautiful… but if you don’t know how to develop a website, you can use WordPress.

Use WP_Query to get the data from the Data base:
https://codex.ww.wp.xz.cn/Class_Reference/WP_Query

Make a template for the page or single in that you can see the data.
Page Templates
https://developer.ww.wp.xz.cn/themes/template-files-section/page-templates/

Here is another option to build the Query:

Template Tag

Just place both functions in your functions.php file. Then adjust the 1st function and add your custom table name. Then you need some try/error to get rid of the current user ID inside the resulting array (see comment).

/**
 * Get "Leaders" of the current user
 * @param int $user_id The current users ID
 * @return array $query The leaders
 */
function wpse50305_get_leaders( $user_id )
{
    global $wpdb;

    return $wpdb->query( $wpdb->prepare(
        "
            SELECT <code>leader_id</code>, <code>follower_id</code>
            FROM %s
                WHERE <code>follower_id</code> = %s
            ORDERBY <code>leader_id</code> ASC
        ",
        // Edit the table name
        "{$wpdb->prefix}custom_table_name"
        $user_id
    ) );
}

How to extend WP_Query to include custom table in query?
http://wordpress.stackexchange.com/questions/50305/how-to-extend-wp-query-to-include-custom-table-in-query