Login to the Admin Panel, go to Developer->Database->Maintenance and click the Remove Sample Data button. Note: Don't use this option on a production site, this will also remove all your existing listings, products, properties etc.
Go to Developer->Logs and click the Purge Cache link in the top right corner.
In version 4.0.3 or higher, you can also clear the Cache from the Admin Dashboard.
The location module contains preloaded locations, but due to the large database size, we are not providing them with our installation package.
After installation, you can import them through the Admin Panel via Settings->Locations->Bulk Import section.
Note: Do not import locations to a production site, this removes all existing locations first and then adds the new ones with a new ID, which makes your existing listings unclickable.
Do not delete a package, this will make all package specific module (listings, products, properties etc.) rows unusable. If you are not using a package, simply change its status from Active to Inactive.