we use eurocamp too but they are the same company.
I think the tents are really well equipped and you don't need to take much. Actually just done my list for next week (6 days and counting )
they have a good size coolbox but you may want to take your own as well.
we take hanging up wash bags. sharp knife. food bags, couple of tupperwares, tea towels!!
we also take a big plastic box for washing up (stacking it , carrying it and then drying it in).
take either a big box or bag (i use those big blue ikea ones) to carry wet towels to and fro pool/beach and also to take stuff to the washing machines (if you will want to do that on hol!)
i always take tea bags and coffee as i like those brands! and i take pasta/sauce for first night tea and long life milk for that cup of tea when we get there!
otherwise obv food is fab there although this year may be more expensive