To practice, create your own bio page.
If you check the [[Special:Categories|Contents]] you will find <i>People</i> and if you select it you will see it has a page name title <i>Category:People</i>. Remember this.
You can also find the page name title in the URL browser's location field like this:
<pre>http://wikisea.net/index.php?title=Category:People</pre>