ListLinePlot[{{1, 2, 3, 5, 8}, {2, 3, 6, 9, 10}, {4, 5, 7, 10, 12}},
PlotMarkers -> {{"\[EmptyUpTriangle]", 16}, {"\[FilledDiamond]",
16}, {"\[FilledCircle]", 16}}, Frame -> True,
FrameStyle -> Directive[Black, Bold, 16], Axes -> False,
PlotLegends ->
Placed[{Style[1, Red, Bold, Italic, 24], Style[2, Blue, Italic, 24],
Style[3, Green, Bold, Italic, 24]}, {Right, Bottom}]]