lincoln is reltiveley safe,
but it is like any other city and there is some crime, burglaries, occasional violence etc.
but usuallt it is very very safe,
i have not personally had any issues with violence or anything, but one of my friends did get attacked and mugged, but it wasnt too serious and he did walk down a dark alley at night on his own,
also there was a murder outside chicken cottage a couple of years ago and just over a year ago there was a murder in the mezz bar in junxions, but that was a gange revenge killing.
other than those 2 things in the past 3 years there hasnt really been any seroius crime of what i have heard.
in conclusion lincoln is really safe and you will be fine.
there are freshers helpers (one of which i am) who will help you get to know your way round during freshers week.