To store a directory under version control you need to create a repository. With Git you initialise a repository in the top-level directory for a project.
As this is a new project, a new repository needs to be created. Use the
git init command to create a repository.
After initialising a repository, a new hidden subdirectory called .git is created. This subdirectory contains the metadata that Git uses to store it's information. If you're interested in the details then use the command line to explore the contents.