Hi colinnorford
/tv-error-code/cs1001 is a broadband connection issue. (The Hub can’t connect to the internet. Please check the cables are securely connected,)
Are you sure it isn't CS1011 error?
If so this ties in with what you've written in your post and is an account retreival error because the box hasn't been fully set up on VM's systems yet, or possibly because the box hasn't been activated.
The first thing to do if it hasn't been done already is to call 0800 953 9500 to activate the box - you will need the box serial number, and your account and area number
If that's unsuccessful it will need to be passed to 2nd/3rd level support to update the systems manually which may take 48/72 hours, and if that fails it will require a box swap.
EDIT You also say you've bought a little streaming box -
VM don't sell their set top boxes, they are loaned out to customers, although there is usually a one-off £35 Stream activation fee. If you did buy a VM Stream box from somewhere then it wouldn't work as it would still be connected to the origianl customers account and they should have returned it to VM (Failure to return it should result in them being charged for the Stream box)