Start by downloading Ubuntu and using it everyday. It's actually super easy to use, IMO easier than Windows or macOS. Then download the language of your choice and start using. When you build something, at some point you'll have to compile and package it, or start a webserver and deploy it, etc..., all good learning experiences. But just using Linux everyday is a good start (and don't go for one of the hardcore distros, use Ubuntu or Fedora).