First Timelapse

[spydervenom]

I'm working on my first time lapse and I downloaded ML and I'm pretty sure I know how to do it but I'm struggling with getting my settings right

I have just been testing a few things outside and everything on my LCD seems very dark. I have a canon t3i and I can't seem to get my settings right. I've adjusted  my ISO aperture and shutter speed to settings that should be appropriate but everything on my LCD seems so dark.  Does anyone have any suggestions on what I should do?