You can create a directory with Ansible using the file module, setting state to directory.

- name: Creates directory
    path: /home/user/my/quite/nested/directory
    state: directory

This will create the directory and all necessary intermediate ones that didn’t previously exist.

As always with file you can additionally specify the owner and group that own the directory, as well as the octal mode. Intermediate directories will be created with the same attributes.

Check the full documentation for other examples of use of the file module.