As Landarc stated you are very optimistic about turn out your first couple days, unless you have been really going overboard on advertisement. In fact I suggest you don't do much of that, for at least a couple weeks, to give yourself and crew time to work out the kinks, and believe me, there will be kinks, then go all out on the ads for a grand opening. Remember it is not a sin to run out just don't make it a habit. Leftover meat can still be good to sell as bbq, and does not need to be used in something else like chili the very next day. For awhile you will probably run out, or toss out food even when you get a better handle on it. If you suspect you have to much and wont sell it before it needs to go have some specials to help get rid of some of it, at least before it all has to go, just don't wait to long. I suspect March is a cold and dreary weather month not a great environment for bbq, so plan accordingly. This should make it clear as mud right? I have to add, unless you have a ton of foot traffic, then adequate parking is essential, and can kill a business if it does not exist, before it ever has a chance to get off the ground. Good luck.
When the going gets tough, I take more fiber.