Low light concert] on d5100 18 55mm?

I need some tips. Some friends of mine are playing in a small venue in a few days and since I like photography and have some basic knowledge they asked me if I could take some pictures of them while they are playing. I love concert photography but I've never tried it. I will be able to be on stage and near the musicians so the zoom won't be a problem. Could you recommend some settings? I've got a nikon d5100 with the kit lens (18 55mm). They said they didn't need perfect or super profesional photos so they don't care if I mess up, they just want some decent ones.

As I see it you have two choices.

Full manual, aperture wide open, shutter speed about 1/50, ISO 800 and try a shot or two.

Full manual with flash. Shutter 1/200, aperture at f/5.6, ISO 200.

Experiment from there. It would actually be to your advantage to shoot some test shots early. Perhaps one of the band members would be willing to just stand under the stage lights and let you shoot tests.

Since you'll be the official photographer, you can take any position you want. Just set camera to ISO 1600 to 3200, aperture priority, lowest f/number and hope for the best.

If you are allowed to use flash, set to lowest ISO and shoot in Auto mode. The stronger the flash, the better.