I am a college student and am working on coursework. I did not want to "try" Adobe Lightroom, I would rather have tried a month of free Adobe Photoshop, because my mother used that program for years, before going on to SketchUp and now Maya.
The trial period does not begin until you install the software so it sounds like there's no harm done if you did not install it.
FYI, the trial period is only 7 days. Adobe changed it from 30 days to 7 days last year.