The create command is used to create a new automation template. This will only create the directory and template files, and will not register the automation. 
blocks create hello_world
This will create a new automation in the .blocks directory with the following structure: 
.blocks/
    hello_world/
        main.py
        requirements.txt
You can edit the main.py file to define your automation, and add any dependencies to requirements.txt. We automatically add blocks-sdk as a dependency. You’ll want to update the blocks-sdk version often to get the latest features and bug fixes.