From the little info we have, it appears you have a dearth of experience, and obviously you have little equipment suitable for recording a band. I see only a few good choices, and one horrible one:
GOOD CHOICE NUMBER ONE:
Forget about sleeping until the project is over. You won't have time, nor will you be able to, anyway.
Borrow money- up to the amount you would be paid for this gig. Then, SPEND EVERY WAKING MOMENT DOING THESE THINGS: Research your ass off as to the best, modest-priced gear you will need, then buy a recording-type mixer with at least 12 direct outs, a recording medium with the capability to record at least 12 tracks simultaneously, at least one SCD mic, several Shure SM-57's or 58's (yes, there are probably mics that may be better, but you don't have the time to mess around with that- go with an industry standard and keep moving.) You don't have the time to wait till good deals come up on Craigslist or whatever, so expect to buy it all new. Find a knowedgable, fair and helpful sales rep at Sam Ash, (IMO, you chances of that are much less at Guitar Center, where they are too prone to hiring people who are more interested in selling gear and making commissions than making sure you get what you need,) who can guide you through the purchases.
Set the stuff up, and again, SPEND EVERY WAKING MOMENT RESEARCHING HOW TO USE THE STUFF AND TRYING IT OUT. Expect your girlfriend/wife to leave you, at least temporarily,) your boss to threaten to fire you, your friends to wonder where the hell you dissapeared to, etc. If those things don't happen, YOU AREN'T SPENDING ENOUGH TIME ON THIS STEP.
Convince a good friend who is good at organization and detail to become your producer. Promise to pay him later. His job is to take care of ALL the non-technical details- and I do mean ALL- way to many to list here. If it does not include maniupulating the gear you just bought, HE does it, not you. Expect him to stop talking to you about half way through the project, and to not say two words to you until the day you pay him. That day, he will make up for all those months or years of silence by saying exactly two words to you- "Thank you." After that, he will never speak to you again. He will go on to get lots of tail from stupid girls who will gush all over him (figuratively and literally) when he puts on stupid fake gold chains and calls himself a "producer." Yeah, right- one of one thousand, just within a one-mile radius.
Buy a pair of large, dark sunglasses and a hat- wear them both during the entire recording session, so the band members can't see the abject fear on your face, as you realize you are in WAY over your head.
When it is all done, you will have a room full of gear you may never use again, major medical bills for everything from hand surgery (due to keeping your fingers crossed for months) to treatment for insomnia, depression and PTSD, no friends, no job, no girlfriend, and probably no place to live (you having been evicted for either noise or failure to pay the rent, or both.)
GOOD CHOICE NUMBER TWO: Be honest, tell them you have no experience recording a band, and pass on the opportunity.
HORRIBLE CHOICE NUMBER ONE: Record them with what you have. They will walk out of the session after a few days (or, if you are very unlucky, half way through,) threatening to sue you for everything you've got (and they will have a darn good case.) Spend every cent on attorney's fees. When it is all done, you will have an empty room where you gear used to be, major medical bills for everything from hand surgery (due to keeping your fingers crossed for months) to treatment for insomnia, depression and PTSD, no friends, no job, no girlfriend, and probably no place to live (you having been evicted for either noise or failure to pay the rent, or both.)
If you go with either GC1 or HC1, by all means, report back here (using a computer at the library, as you will no longer own one) about how it went.
LOL!!!! That was one of the funniest posts I have ever read!!!!