Installing ROS 2 and Gazebo

# authorize our GPG key with apt 
sudo apt update && sudo apt install curl gnupg2 lsb-release
curl -s https://raw.githubusercontent.com/ros/rosdistro/master/ros.asc | sudo apt-key add -
# And then add the repository to your sources list:
sudo sh -c 'echo "deb [arch=$(dpkg --print-architecture)] http://packages.ros.org/ros2/ubuntu $(lsb_release -cs) main" > /etc/apt/sources.list.d/ros2-latest.list'
sudo apt update
sudo apt install ros-foxy-desktop

Install argcomplete

sudo apt install -y python3-pip
pip3 install -U argcomplete

try ros

ros2 run demo_nodes_cpp talker

install colcon build

sudo apt install python3-colcon-common-extensions

install gazebo

sudo apt install ros-foxy-gazebo-ros-pkgs