I only need to cut 2D parts so my workflow/software is:

CAD: AutoCAD (expensive and probably more capable than hobbiest needs) - create drawings and convert into dxf file(s)

CAM: dxf file into Vectric Cut 2D (excellent, simple to use, intuitive, good forum/support, around £120 seem to remember) to create toolpaths and generate Gcode

PostProcessing: MACH3 (full version, around £115) to turn Gcode into commands sent to the CNC machine to cut out parts

Works well for me for cutting out plywood, balsa, liteply, and the occasional aluminium part.