Help please to set up new TomTom.

Gandam

We have just purchased a Camper & Caravan TomTom. I am feeling a bit stupid about what details I enter when setting up the vehicle entries. I know that I have to enter the combined weights and lengths of car & caravan but I am not sure about what to enter
for maximum axle weight,is this referring to car, caravan or both? When I  look at the specs for car & van on line I can get different values for gross weights & kerbs weights, MLO, Payloads &  MTPLM, totally confused!! what do I enter as the maximum axle
weight  please??