The best thing so far is that you can use Terraform everywhere - AWS, Azure, GCP, and many more. This way you don't have to learn the underlying API language, you can just learn HCL. Start with installing Terraform using your OS of choice.
Installing docker is easy and well documented at Docker Docs. Here are some quick commands you can use to get started with Docker containers.
Docker version:docker --version
List all images that are locally stored:docker image ls