While WordPress allows you to accomplish a LOT within minutes of the initial download, there really shouldn’t be a limit to the things you can do…and there isn’t. WordPress extends 3rd party plugins that can be developed and shared by anyone.
These plugins are capable of all sorts of things, like introducing eCommerce functionality, integrating Google Analytics, creating dynamic photo galleries, and anything and everything else you can imagine. At the time of this writing, there are 4,245 official plugins for download via the WordPress Plugin Directory.
The first thing you’ll want to do is install the One Click Plugin Updater. This allows you to install other plugins directly from the WordPress admin, which alleviates the need for downloading and FTP’ing files.