Autodesk's deep catalog of CAD and CAM software is well known for being easy to use and highly powerful for creating pretty much everything. A new feature you may not be aware of is that Fusion 360 and CAM 360 now support exporting gcode for Shapeoko.
Youtube user jgilbert20 breaks it all down and shows you how to take a 3D design to finished pieces:
Autodesk's Fusion 360 and CAM 360 are available to try for free from Autodesk's website for 30 days, and are free for students and enthusiasts. Thanks Autodesk!