If you would like to learn how to install Magento, you might find the below resources useful. They show you how to create a Ubuntu Web Server from scratch and then install a clean copy of Magento 2.
How to create a web server for Magento 2.2 (OLD)
How to upgrade Magento 2.2 to 2.3 (NEW)
How to create a web server for Magento 2.3 (NEW)