General facts about the city : 'New Orleans is of course amazing. The French Quarter is full of hobo kids as well as drunken vomiting tourist frat boys. A friendly place. Don't let the bullshit about ever since Katrina it's been very dangerous scare you- yeah there are gang war neighborhoods, but if you just hitchhike in you can hang out in the French quarter and be fine. Seriously, even if you are in a gang neighborhood people leave travelers alone- you have a bag/backpack and a cardboard sign- you're basically homeless- you don't belong anywhere/you belong anywhere. Don't worry about bad neighborhoods- you're a bum!
West toward Baton-Rouge, Lafayette, Houston, Texas
Get the streetcar (tram) that goes on Canal Street (which runs from the Mississippi river and all the way to a cemetery). I costs $1.25 for one ride or $1.50 for transfer ticket if you get another bus before it. Take it until the last stop, called Cemeteries (far from the river and you'll see tombs everywhere).
From there, even though tempting to get to the I-10 straight, walk up to City Park Ave, turn right on it and then take a left on Canal Blvd. You'll see a small loop with 2 bus stops on it (don't walk too far, take the 1st loop). Here take another bus, the E1 route of the Jefferson Transit . It costs $1.50, for which you should have exact change because the driver does not provide change. The E1 route is often called the Veterans' bus since it goes far on Veterans' Blvd.
You need to get off before the I-10 on Veterans' Blvd. It's about a 15-25 minute ride. You'll be on a long boulevard for a while and you'll see at some point the highway. Just hop off before you pass under it or tell the driver you are a hitchhiker and need to hitchhike to Baton-Rouge and he'll tell you the spot. Look the map and you'll see where the I-10 and Veterans Blvd intersect. You need to stop just before it.
There you walk on the onramp to I-10 West. Use a sign! You'll see lot of gas stations on the way
Loads of free food serves in New Orleans if you're into that sort of thing, the Hare Krishna dinner is even better than Hare Krishna dinner usually is and they basically leave you alone religiously unless you're actually interested.
Have a look at this: http://www.bestofneworleans.com/gambit/free-bar-food/Content?oid=1279433 It's a bit out of date, but it's got lots of places that serve free/cheap food!