Get familiar with ROS
The Robot Operating System (ROS) is a framework for writing robot software. ROS uses concepts like nodes, topics, messages, etc. Get familiar with them by searching on the web. You can start reading at: http://wiki.ros.org/ROS/Concepts
Install basic set of packages
sudo apt-get -y update && apt-get install -y \ nano \ vim \ git \ mercurial \ cmake \ build-essential \ automake \ libtool \ libtool-bin \ pkg-config \ wget \ curl \ unzip \ libjsoncpp-dev
ROS have several distributions (versions). Install ROS noetic distribution, which is the one compatible with ubuntu 20.04. Follow the instructions on this webpage. Install the Desktop-Full version. Make sure you follow at least steps 1.1-1.7 in the webpage .
To test the installation, run in a terminal the ROS core:
Then in another terminal you can type:
You should be able to see at least the following: