Hello I want to create and add pages; Most visited, best rated, recent photos and put the links in the header of my site. Home|Most visited|Best rated|Recent photos|
As on the default theme at piwigo: http://www.piwigo.org/demo/index.php?/categories

Can anyone help me please?

Create so called "static theme pages" or those within your theme:

• http://www.zenphoto.org/news/theming-tutorial/#part-3-advanced-theme-functionality (assumes you are familiar with part 1 and 2 already)

Enable the image_album_statistics plugin and add the related functions

• http://www.zenphoto.org/documentation/plugins/_zp-extensions---image_album_statistics.php.html
• You might need to update your theme's css so it really looks like you wish.
• Then modify the theme used to have links. Statically via html might be the easiest for you. Otherwise setup the theme with a menu via the menu manager plugin.

For some of these "categories" we call "statistics" dynamic albums may also a be a way.
http://www.zenphoto.org/news/how-to-use-the-dynamic-albums-feature/

Ok thank you but what are the php features that displays the best pictures, the latest.

This is my header

See the doc link for the image_album_statistics plugin I already posted.

printRSSHeaderLink('Album',getAlbumTitle()); ?>
That line will not work as static theme pages are outside of any album or else context. Use something like printRSSHeaderLink('Gallery', gettext('Gallery RSS')); instead. Please take the time to read the theming basics if you haven't already and also look at the official themes for some examples. There are also basic example theme pages available within the tutorial.