Close to New Orleans is Bayou Segnettte State Park which gets nice reviews and Ponchartrain Landing which is ok. Best thing to do is get the Allstays App. which would enable you to plan or find sites all the way from Ca.
My recommendation would be to stay on the same side of the Mississippi River where you will be visiting your son.
1998 American Eagle 40' EVS, 2011 Ford Edge, Falcon 2 tow bar
DW and 2 DD's