Qiyuan

Hello, I need to draw a cable crane on a slope we measured. I already digitalized the measured data from the slope using R, but I also need to draw lines as on the attached Image. I'm really new at paint.net, so I need a lot of help. I need to print it on A3, that I solved quite easy by setting the canvas size. But how can I make a layer that looks like normal milimeter paper for technical drawings? I used the plugin "Gridmaker", but it is not making the wanted grids. If someone could help me with this problem I would appreciate a lot. Best regards! What I shall make: What I have so far: