The ROS Wiki is for ROS 1. Are you using ROS 2 (Humble, Iron, or Rolling)? Check out the ROS 2 Project DocumentationPackage specific documentation can be found on index.ros.org
Now, to test your installation, please proceed to the ROS Tutorials.
Wiki: melodic/Installation/PostInstall (last edited 2018-01-30 16:16:17 by ChrisLalancette)