On I-10 just east of Lafayette, Louisiana you'll drive across the Atchafalaya swamp (largest swamp in the US). Watch your speed on this 18 mile+ bridge. The posted speed limit is 60 mph and the Louisiana State Police and the Parish (County) Police departments are serious about that speed limit there. Most other places (on the interstates) you're good until 10 mph over the posted speed limits.
If you stay on I-10 (instead of going across I-12 to Miss) you'll drive through New Orleans, not my favorite place, but is very popular with the tourists and everyone should go to the French Quarter at least once in their lives. (Don't make any "bets" with the local hustlers in the Quarter.) Also, the National WW2 museum is in New Orleans and it is fantastic. Eat some seafood while you're in New Orleans. Try a 5 star while you're there, but also stop at a Mom & Pop cafe to see what the locals really eat. After experiencing seafood it in south Louisiana, you'll be forever disappointed with seafood anywhere else.
New Orleans is only @ 90 miles from Biloxi, so you could make a day trip while you're there.
When you leave New Orleans cut through Metairie back to I-12 and you'll drive across the Huey P Long Causeway across Lake Pontchartrain (longest bridge in the world). It's a toll bridge and will cost 2 or 3 dollars.
North of Baton Rouge is the Port Hudson battlefield and numerous plantation homes. There are also many of the antebellum period plantation homes in south Louisiana closer to New Orleans. LSU is in Baton Rouge and a drive through the beautiful campus isn't too much of a detour from I-10. Stop for a moment and see the LSU Tiger's mascot...his "home" is amazing in itself.
(I-55 will take to I-10 just before it goes into New Orleans)