If it is a swan neck towbar/ball then you should be able to tow a van with a stabiliser hitch, if it is flange (the towball bolted to the bar itself, then you need to check that it is also compatible otherwise replace with an 'Alko' head to be OK with stabilser hitch on the van. 13 pin is the current type of socket, for trailer towing there might be just a 12N (Road lights etc) or if wired for an older caravan a 12N (Black) and a 12S (grey that is for auxiliary functions like charging the battery and running the fridge when in transit. If the ball has not been used for a while it will need some cleaning with fine grade wet/dry paper to remove rust and muck!
Incidentally following Covid and overseas restrictions you will find that used or new vans are in short supply, but as has been said, check the kerbweight of the car, and aim for about 85% of the weight (or 1300 whichever is lower) for the caravan. If you look at the list in the back of the magazine then MIRO and MTPLM are quoted, but consider the latter figure in your comparison. If you browse online you will find most dealerships list this figure too for vans they have for sale.
Ask any questions you have on the Forum - you will always receive prompt answers!
Happy hunting!