If you want to learn this stuff I made a tutorial series. I think I explained it at a level that is simple enough.
Basically the hard part is learning the complicated vector drawing program, eg, Inkscape, and then applying Fritzing rules to the drawing. It’s kind-of closer to CAD software than raster drawing, eg, Photoshop. I’m still not brilliant at Inkscape, and have to look up how to do the complicated stuff, but I now use INK to do everything technical.