- the one that you bought - must be hosted on a server before you can run a web site on it. The server space that you are using at the moment will be that which is provided free by NTL acting as your ISP. That means that by default any site you upload will have the NTL users' reference as part of its url - homepage.ntlworld.com followed by your site name.
I'm not too familiar with the NTL system, and it's possible that they will host your domain for you. This would involve you in an anual fee for the hosting, but then you would be able to have your site on your own domain name. Otherwise you'll need to enter into a hosting agreement with one of the hundreds of hosting companies in the UK.
I suggest that you speak to NTL and find out what the situation is (and what they might charge you for hosting), and then come back here for further advice.