I presume your Virgin box provides the television content. I have no idea if you need the arial or not. It being there should not impact the ethernet connection. IPV6 is an addressing scheme for the internet, I don't think it needs to be enabled, unless the Virgin box is using it (unlikely).
Think of it this way. Outside your house the cable is ready to provide tv video and audio, as well as connectivity to the internet for data. But it is on a line that is being shared by hundreds, maybe thousands, of other users in your area. So the Virgin box sorts out those thousands of possible signals for the one for YOU. You tell the Virgin box you want, let's say, BBC1, and it sifts the signals from outside to find BBC1 and translate the digital signals there to audio and video that it then feeds across the HDMI cable to the TV so you can see and hear BBC1 when you select the HDMI input on the TV.
In the same way, that Virgin cable has internet traffic to and from that same hundreds/thousands of users, all interlaced. Your Virgin box has a specific numeric address, called the IP number (IP = Internet Protocol). IPV6 is version 6 of the IP address scheme and was adopted because the previous version, IPV4, had run out of numbers. IPV6 has a potential for 3.4×10 raised to the 38th power, or 3,400 followed by 35 more zeroes. So the Virgin box has an address in the Internet with that IPV6 number. Inside your house, the Virgin box becomes your network administration box, and it issues an address to each of your devices that attach to the network. Typically that internal IP number is the old IPv4 format, where it is in the form of x.x.x.x, where each "x" is a number between 0 and 255. However, the generally agreed format is that your network will have numbers in the form either 10.0.x.x or 192.168.x.x. For example, right now my MBP has an assigned IP number of 192.168.1.64, assigned to it by my own version of the Virgin box. The Virgin box keeps a table of numbers it has assigned and when it sees traffic either from the devices, wraps it in an envelop with an appropriate IPV6 format and sends it out into the Internet, and when it gets a response, it opens the envelop and sends the data to the appropriate internal IVP4 address. Imagine internet as a postal system that takes your outgoing mail, puts it in a big envelope and sends to the world at large. The central post office then directs the articles in the envelop to the right destinations. Then when mail arrives for you at the post office, it's bundled in an envelope to your address and it gets directed to your house where it is delivered for you to read. The Virgin box is the postal service in that scenario. It translate the outside data to your internal network so you can see what you want on your computer/TV/whatever is connected to the Virgin box.
So, what I think is that you should just leave the defaults on the TV as they came, then connect the Ethernet and see if the TV connects. It should. You may have to give the access code to the network (should be on the Virgin box) so that the Virgin box knows this is an authorized device, but once that is done, you should have Internet access on the TV in addition to the TV signals from Virgin.