If you've not visited the French Quarter in N'Awlins I would suggest you come back that way and eat some Beignets and drink some wonderful coffee from
Café Dumonde and on to Central Grocery or Napolean House for a muffuletta. You can stay right downtown within walking distance of it at
French Quarter RV Park. It is expensive but we splurged on our way down to St Andrews this summer. It is like a parking lot but very nice and level and the showers are a private bathroom and very clean. We only walked to French Quarter during the daylight hours but did not feel threatened at any time.
You will come through Gulfport and Biloxi. After visiting French Quarter You can then take I-49 back up to I-20. Nice Drive.