First Tip, don't bring too much!
You really only need the basics:

• Ideally Sleeping Bags (or Sheets & Duvets) and Pillows
• Towels
• Comfortable/sensible shoes for driving​ and walking
• Check the weather and pack clothing accordingly, but keep to a minimum
• Don't forget your favourite game/s and toys for the kids
• A good book/magazine
• Food and Drink - due to limited fridge/storage space, we recommend buying the essentials only and then shop on a daily basis for meals.  
• Paper Towel, Cling Film & Tin Foil is useful
• Small bottle of cooking oil
• Plastic bags for rubbish and wet/sandy stuff!
• Wet Wipes are priceless when camping!
• Gadget charging cables 
• A Head Torch is very handy too!