I try to setup magento on my server and stuck in configuration step.
Not sure what going on. I'm quiet new in Magento.
I had the same error and my problem was the file permissions were incorrect.
To fix it, I ran the recursive command to ensure that the Apache service has read permissions.
sudo chmod -R 755 ~/Sites
As @OST Agency have stated, this is most likely a file permissions issue.
However, I wouldn't recommend just CHMODing everything to 755 as it depends entirely on your server environment.
You will need to contact your server administrator or hosting provider to know the proper file permissions to use and apply it for your files and directories.