After installing oh-my-zsh, I get fatal message when 'git init'

Question

I recently installed oh-my-zsh (using theme 'cordial'). The problem is that when I 'git init' I get this message

fatal: ambiguous argument 'HEAD': unknown revision or path not in the working tree. Use '--' to separate paths from revisions, like this: 'git [...] -- [...]'

I switched to bash and ran 'git init' and it did not give me the message, there is no problem.

I figured out that once I made an initial commit it stopped giving me the message but I don't know how I fix this problem before I commit.

Any suggestions would be greatly appreciated!

Thanks in advance.