Assuming you own the wall and it is not protected by any 'listed or conservation' status, then you are entitled to knock the wall down.
You are not allowed to drive across or on a pavement unless you have a council approved dropped kerb.
However, I don't see how that could apply to manhandling a non-motorised caravan onto your drive, if you could do it that way.
You do need to read your deeds though - many properties have covenants that prevent storing caravans, boats etc on their frontages.