This is a very bad idea. You said desperate and you are right. Conditions are desperate this time of year in N.O. Since I'm a native and lived there until Katrina (48 yrs), I know what I am talking about. July and August are the "down months" in N.O., as winter is downtime further north. You don't garden in July/August, you just water and trim what needs and sip iced tea (or beer) under a fan, without moving much! But if you insist on planting now, and I'm guilty of it too, you will do best in later evening (mornings are very humid), you will have to water very frequently to get the plants established. Some good plants that are tough are lantana (several varieties/colors), shrimp plant, cannas, zinnias, mandevilla vine. The ideal time to plant in N.O. is late fall/winter like Nov to Jan. Be very careful with yourself as to staying hydrated and retreating to cool A/C when you start feeling drained, get a headache, etc. Signs of heat exhaustion etc. Been there, done that.
Laurie

Laurie, excellent advice!

Msnola, I second lantana as a good choice for this time of year. Lots of color options and it generally thrives on neglect. It's perennial and will flower until first frost.

Your best bet is to do research and plan for the fall when conditions are more conducive for success and more comfortable for you!