Assuming caravan is level & power is getting through to fridge then usual problem if fridge is working on gas & 12v while driving but not on mains elecric is failure of 230v element. These can be replaced, cost of element around £40 depending on fridge. Diy is possible if you know what you are doing.
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.