Welcome to the forum and Eriba ownership.
Early advice:- towbar, number plate and sticky things to fit it, insurance [Try Ripe, Cover4Caravans, Lifesure, Comfort, Grove & Dean]. With a Puck there is always debate on whether you need towing mirrors. If the back of your car is wider than the Eriba then legally you do not, but the extra visibility given by [Milenco are a good choice] Finally don't rush out and buy anything to go inside the van, use your camping bits for the first trip away [near home]
Colin