Hi Jacki.
You don't need to be super fit, for this trip. As the walking is done on decent paths or tracks in general. And is very relaxed and subtle. However there are one or two short inclines, and a little bit of a goat type track to encounter, And all of this will be on the main Red Wine Trail walk. My advice is though, having done this 3 times before, is go prepared for both rain and very hot sun, meaning water proofs, top and bottoms,hat,sun glasses,sun lotion, and some water would be ideal.I say both half of the water proofs, as on the main walk, the second half of it. Is all open with little shelter. A good pair of walking boots would be ideal, but not essential as you could do this walk in trainers, however if the weather isn't kind to us, then they could get ruined.
Andy