the first gig i shot was with a manual focus helios 58mm f/2 lens...it was a nightmare!
if you could borrow a fast lens from someone it'll make your task a lot easier. the 50mm f/1.8 is pretty cheap and will be useful in your kit bag for more than just gig photography.
tom made some good points, pick your shots-don't just spray and pray! i usually start at the same base point..iso 1600 @ f/2.8 and then work from that to get a workable shutterspeed.
i've been in situations where the venue is like a black hole, and the limits of my gear are stretched to their limits. a kit lens will struggle, even at 3.5 at the wide end. at 5.6 on the long end it will be pretty much unusable to be honest.
if you only have access to the kit lens you might have to make do with f/3.5 @ 18mm, even then it might be necessary to 'push' the exposure at the editing stage. if you don't already shoot raw you should do so because the ability to bring an extra stop of light out can be really beneficial in these situations. you will be working with a lot of noise with the combo of high iso and pushed exposure so you'll probably want to go black and white to hide this a bit.
use ai servo to track the moving band memebers, center af point because it's the most accurate and spot meter for your subject. shoot manual and set your iso to it's highest setting and aperture to it's widest setting, if you can get close to workable exposures shooting at something above 1/80(ideally more) stick with it. if there are pockets of light created by the stage lights wait till the band memebers step into them before taking your shots and hopefully you can work around your limitations.
use the first song as a 'sighting' exercise to see what the lighting is like, get an idea of what settings you'll be working with and watch what is happening on stage and if there are any 'hot-spots' that you can use to your advantage.
hopefully a little of this will be of use to you