Where can I find the setting for this plugin?

In admin menu, click on WooCommerce -> Settings, and switch to Integration tab

2.1.4 - 28/03/2017

• Fixed Warning with WooCommerce 2.6 onwards
• Added license & authors information
• Added some minor security changes
• Added screenshots to repo

2.1.3 - 19/09/2016

• compatibility with new WooCommerce

2.1.2 - 15/01/2016

• Fixed issue with not tracked orders

2.1.1 - 08/04/2015

• Fixed issue with missing categories
• List of contributors was updated

2.0 - 31/09/2014

• Rewritten by Piwik PRO team
• Feature: Plugin allows to integrate with Piwik PRO instance
• Compatible with WordPress 4.0

1.0 - 22/11/2013

• Feature: Plugin checks for required WooCommerce version or doesn't do anything
• Tweak: Split up logic and output into classes, powered by a lean bootstrap script

0.1.1 - 17/05/2013

• Fix: Make this compatible with versions before WooCommerce 2.1

0.1 - 02/05/2013

• Initial release to get this up on wordpress.org

1. Download the plugin file to your computer and unzip it
2. Using an FTP program, or your hosting control panel, upload the unzipped plugin folder to your WordPress installation’s wp-content/plugins/ directory.
3. Activate the plugin from the Plugins menu within the WordPress admin.
4. Go to WooCommerce settings, switch to "Integration" tab and integrate with your Piwik installation.

Or use the automatic installation wizard through your admin panel, just search for this plugins name.