Let's do a few basic things that will help you get started.

Create snapshot

Find your container ID:

  docker ps -a

Create new image from your container:

  docker commit acd51d77124b name_of_your_new_image

List all your images to see your recent snapshot:

  docker images

Restore from your snapshot

Start a new container from your image:

  docker run -dit --name your_new_container_name -p -p name_of_your_new_image

Stop your running container:

  docker stop your_new_container_name

Start your container again:

  docker start your_new_container_name

(Optional) Remove changes

Delete the container you just created (make sure it is stopped first - see above):

  docker rm your_new_container_name

Delete the image you just created:

  docker rmi name_of_your_new_image