I always get a brownish-green hue around me when I edit out the green screen in after effects. Is the problem the lighting, green screen editing, etc. Can someone please help.
Lighting could definitely be part of the problem here. Typically, for green screen work, it helps to have a light between yourself and your green screen to get rid of those shadows behind you (sort of like a backlight).
To fix your current footage, I'd increase the sensitivity of your chroma key in After Effects, since it looks like AE is essentially leaving a thin outline of the screen around you. If you increase your tolerance, you should see that outline shrink a bit. Feathering the edges of your image can help with this, too.