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
Gazebo documentation is in the stack page and the corresponding tutorials.
Wiki: gazebo/Tutorials (last edited 2009-10-08 16:16:24 by BhaskaraMarthi)