If the model is Cello C16230FT2S2 then it is 12V and draws 2A or nominally 24W. The box in the mains lead is a transformer - technically a Switched Mode Power Supply - which converts the incoming 240Va.c. mains down to (again nominal) 12Vd.c.
If your (supplied?) 12V cable has a cigar lighter power plug on the end then you will need one of
these. This will be correctly wired to plug in to your caravan - it will only fit one way round as one pin is bigger than the other.
Two other points:
As your caravan is of the older variety it will only have the older-type coax cable on the aerial system, that is a coaxial cable with a very thin and strung out outer screen rather than the tighter woven screen with a copper foil under it as used these days. A side effect of this is that, depending on TV signal strength, someone moving around in the caravan may cause the picture to break up momentarily. Your aerial may also be a 'flying saucer' variety - this is a Status 300 series. Whilst it may not be quite so effective as the more modern Status (or Vision) 500 series directional type it will still work quite effectively in most places. Be aware that there is NO SUCH THING as a 'digital' TV aerial, any aerial will receive both analogue and digital - it is what is connected to the other end (i.e. the TV) that defines whether it is analogue or digital.
Second: if this is the model you have bought you may not realise that it also has a built-in satellite receiver which means you will be able to get TV anywhere in the UK or Ireland (and some parts of Europe) if you have the right aerial (dish) equipment.