Diferent colour lines and cannt push pull

Hello to all
Im new to sketchup and have done a drawing that has dark black line and light black lines on curves and straight lines.
I want to push pull some parts and all drawing comes up.
Not sure what ive done
Many thanks
Untitled.skp (150.5 KB)

The dark lines are Profile lines and show that the face hasn’t cut properly.
I suspect the fact your model is 81km long is causing problems.
Here it is repaired.
81km.skp (89.6 KB)

Thanks for the repair
How did you do that?

Is there a way to change from km to meters

There are several ways to resize. Here I used the Tape tool.
Select the tape, tap ctrl key to remove the little cross, click a point, click a second point of a known length and immediately type (in mid air) the length you want and hit enter. It will ask if you want to resize the model, say yes and it will change to that.

As to the fix, I removed the main face, selected the inner edges and used a add faces plugin, then the same for the outer edges, finally I used a weld plugin to finish fixing the couple of lines that didn’t cut.
Took longer to explain than do.