Ok I regularly stay there since it's not far from me. We are over there all the time.
Nola can be super cheap! Hotel prices rise during festivals. But it's hard to keep up with those.
Pretty much a hotel in the French qtr, central business district or warehouse district/convention center area are all within walking distance. There is a nice residence inn (on st Joseph) in the warehouse district that's my go-to when everything else is booked up. It's a little further out but seriously not bad. Or it's just a few blocks up to the streetcar so that's an option too. Plus uber is good there.
I ALWAYS try Priceline first!
One of those three areas for 3.5 star and up, I've gotten it as low as $45 bucks a night. Just depends on what's going on in town. Often whatever is going on won't affect you much with the exception of Mardi Gras. The French qtr fest will affect you but I find that one to be in a good way. Music stages set up everywhere and food galore! It's hard to have a bad meal in Nola!
Definitely do the zoo, aquarium, ghost tour (we've used
https://www.frenchquarterphantoms.com/ghost-and-vampire-tour and liked them), check out the cemeteries, wander the quarter (minus bourbon!) check out Royal though, one block over towards the river, WW2 museum is amazing, you can ride the riverboat, see some plantations that aren't too far away, swamp tours aren't too far from town either.
Just be aware that any hotel down there will charge extra for parking. Sometimes there is a paid lot close by that may or may not save you money. But I always opt for the valet--it just saves a big headache. I also don't drive as long as we are anywhere down there including the garden district. We use the streetcar for everything except for the zoo. Free parking, might as well, although again the street car passes right in front of Audubon park with the zoo to the back of the park. It's a beautiful walk and not far. Totally worth doing!
Wow this was way longer than I meant! Sorry for rambling! It's my fav city and I'm lucky to have grown up in the area.