Campervan travel in Europe

Hi,
we are a family with one little nine month daughter and we've just bought a campervan to travel around Europe. We would love to hear from anyone who has done this before, on a limited budget, and who can offer any advice?? What things are absolutely essential to take, is it necessary to stay in camping grounds and any other tips would be most appreciated!

Thanks very much,
Ned and Liv and Mai An

Campingground are often far from the city.

Better to stay in the city centre and take showers at public baths. cost €1.