How to plot two sets of data on one ListLinePlot

Instead of ListLinePlot[ list1, list2 ] use ListLinePlot[ {list1, list2} ].

Or

p1=ListLinePlot[list1, PlotStyle -> {DotDashed, Thick}, PlotLegends -> {"list1"}];
p2=ListLinePlot[list2, PlotStyle -> {Dashed, Black}, PlotLegends -> {"list2"}];
Show[p1,p2]