Quick Camera Question

I did searchbar this but couldn't find anything quick enough.

I'm at Tignes Glacier and I have one day left. Took my Canon Rebel XTi up today to try some photoing, but I'm having trouble getting the settings right for the light conditions.

Stupidly I didn't bring the manual, despite this being my first real chance to use the camera.

It's cloudy on the glacier, and I'm taking photos of my friends in the park, but the end result is either underexposed and dull-looking, or way overexposed if I fiddle with the settings.

I know I sound like a complete douche, but can someone tell me how they set up their camera?

I don't have long tomorrow since we have to leave about 3:00pm to catch the flight home, so i don't want to be spending all morning working it out for myself.