We stayed at camping Les Puits Tournants in May this year for 6 days. Small site, small swimming pool and a fishing lake which my husband loved being a fisherman. It's in the Camping cheque book page 37. A good central place for visiting the area, also the WW1 museum at Albert is well worth a visit. We didn't manage to visit Amiens but that might be worth a visit. If you google Albert WW1 museum france it will tell you about the museum.
When we did the poppy trail, we stayed at a site in Amiens which was basic but clean and the staff spoke english and where helpful, it is in the caravan club european site brochure, it is called Parc des cygnes.