Hi.
It’s been 5 hrs and no one answered your question. So rude, isn’t it? After reading your question, I have speeded up writing my ‘how to install Ghost’ article. You know… I am excited just like you as I also installed Ghost couple of weeks ago in a sub-directory.
Well here is your vpsdime pathway to install node.js and Ghost.
sudo apt install nodejs npm
Go to your root directory and delete dummy page i.e. in Nginx
/var/www/html/
Now install Ghost CLI, and then run:
ghost install
There you go! Here is a link to learn more https://docs.ghost.org/docs/install
Post back if you run into any problem. The forum is very helpful, indeed.