OpenSCAD is a programmer’s solid geometric modeler. You can make complex objects from a combination of spheres, cylinders, and rectangular volumes. However, sometimes, you have more organic shapes that you need to model, like the knight in a chess set. That’s where an interactive modeler comes in handy. You can use Inkscape to draw a 2D shape, and extrude it in 3D in OpenSCAD.
I’ve found the tutorial I’ve linked above works, but you have to make sure that you make the paths segments, or else OpenSCAD won’t display it. Also, note the dimensions that you’re drawing in, since you’re drawing on A4 paper by default in Inkscape, the extruded model in OpenSCAD viewer might just be off screen, so make sure you zoom out.
Also, every time you change the DXF file, you need to flush the cache in the OpenSCAD viewer in order to get the DXF file to reload. It’s under “Design -> Flush Caches”. And then you can reload and compile (F4).
In addition, in your .scad file, loading the file with linear_extrude is deprecated. Use this instead:
where import() is the child of linear_extrude. Hopefully, this will help you avoid some pitfalls of modeling with DXF files. Happy modeling!