Are you working in your office environment where you can't install and play with docker?
If yes, this article is for you. Let's start exploring docker environment.
Go to https://labs.play-with-docker.com/ . This is provided by Docker exclusively as a playground where you can play and learn docker.
Login to docker using the id created while registering. If not done already, go here to register.
After logging in, it will redirect to "https://labs.play-with-docker.com"
Click Start and your session will start.
Click "Start Instance" to start your docker instance which is valid for 4 hours.
You can open the port which you want by clicking on the "Open Port" button.
Get started with calling basic docker hello-world image
docker run hello-world