Exposer help for the nikon d3100?

I have a nikon d3100 with my 55-200mm lens on it and I have no clue on how to change the exposer:/ help?

The subject is to complicated for me to answer you fully here,

try youtube for tutorials --- photography how to change exposure

Time to sit down and READ & STUDY the Owner's Manual for your camera and learn how to use it.

There are two ways to let the camera assist you in setting exposure. One is Aperture Priority - you choose an aperture (aka f-stop) and the camera sets a shutter speed that will give the correct exposure. The other is Shutter Priority - you select a shutter speed and the camera selects an aperture (f-stop) that will give the correct exposure. NOTE: If there's insufficient light the camera may not let you take a picture.

Your Owner's Manual will show you how to access these settings. It will also tell you what to do and how to do it if you're using either of the modes I listed and the camera refuses to allow you to take a picture.

Spend time at these sites:

http://www.kamerasimulator.se/eng/?page_id=2
http://www.digital-photography-school.com
http://www.photonhead.com
http://www.illustratedphotography.com/photography-tips/basic

Read these books by Bryan Peterson: 'Understanding Exposure' and 'Understanding Shutter Speed'.

Hint: Its spelled 'exposure' not 'exposer'.