Morning Andy
I tow quite a bit, not a caravan but 2 fat horses in a trailer (great having a wife with a hobby !!) as John said in his response 1st check the towing capacity for your car/model/year my guess would be 700kgs un-braked 1500kgs braked but that isn't all you need to consider there is also the "nose weight" (the load on the Tow ball). Also don't just buy a 1500kg Van and then load it up with all your kit for an adventure week away, you will be overloaded and may run into issues with insurance/law if the worst happens.
As John says do your research there is plenty of information on line, with regard to "Nose Weight" don't buy any fancy bits of kit to check a piece of wood cut to length and bathroom scales work for us, yes still needed when Wifey loads water and hay in the front of the trailer?? There should be some weight on the ball but not to much and you definitely don't want it lifting the ball.
Google is your friend
Dave