Okay, well, you're not filling in your information but using the default information that is intended only to tell you what to add. For instance:
hdx: You need to replace that with 'sda5' or whatever the number of your partition is. 'oldhome' you need to replace with the actual mountpoint you are using.
mount /dev/hdx /mnt/oldhome
You need to provide the exact path on your machine. You are also missing half the command as the full command from that link is:
sudo cp -Rv /media/disk1/home/yassys/*
You're not copying the file to any destination, thus the missing operand.
sudo cp -Rv /media/disk1/home/yourusername/* /media/yourdestinationdrive/yourdestinationfolder/
What was given were examples only; they are not intended to be used 'as is', unless the paths and names on your machine, by some freakish coincidence, happen to match the details in the examples.