I have realised one mistake - I had the 'style.css' as a folder with the file saved in it, rather than as a file.
I've corrected that now, so my style.css is a file.
I now have the following in my style.css file -
\f0\fs24 \cf0 \cb2 /*\
Theme Name: Blackbird Child\
and when I search it on wordpress the problem is now:
The parent theme is missing. Please install the "blackbird\" parent theme.
I think/hope once I fix this it will be created!