And now I would tell you how to show tag cloud in a block.
Solutions

Use a snippet to show tag cloud for a specified vocabulary
Use tagadelic module

Snippet to show tag cloud for a specified vocabulary
Shows tag …

This article will tell you how to disable (hide) block in a few methods: through block settings, PHP-snippet, SQL-snippet, etc.

Problem
Get information about users who are currently on the site

Now I would tell about configuring what block content appears in your Drupal site’s sidebars and other regions. This is very simple and available even for beginners.