Thank you! :) Honestly, just be patient. CAD software can be very hard to learn, especially if you've never dabbled with this stuff before. I personally use fusion 360 because its what i'm most comfortable with but there's lots of good software out there such as blender and shapr3d (there's more than just those 2, those are just the first ones that come to mind rn). I would recommend watching youtube tutorials where they have you design pre-determined projects. That way when you know what you want to make, you have a wide variety of knowledge about the software you're using There are more simple programs out there such as Tinker cad and Mesh Mixer, but if you want to design things such as this design, i highly recommend trying one of the 3 software's i mentioned above.

Thanks for your reply. I used Shapr3D for a while now I'm using Fusion 360 with a YouTube tutorial from Product Design Online. It's good to know I'm on the right path. Thanks again, happy printing!