It seems there are a few steps of which you might be unaware:
First, you'll need a program that can turn your 2D picture into a 3D object. SketchUp can be used for this step, but it requires use of features I'm not familiar enough with the help you further on this step.
Second, once you have your 3D object, you'll need to export it to an STL or OBJ file. This is something SketchUp can do.
Third, you need a program that reads that STL or OBJ file to create the G Code @DanRathbun mentioned. Some of these programs - called "Slicers" -- can directly control your CNC machine. Others require you to save the G Code file they generate to a USB stick or SD card, which is then loaded into your CNC machine.
There are many 3d printing services that can replace the third step. You upload the OBJ or STL file, then they do the CNC work and ship the result to you. Unless you have your own machine - or a local Maker space - or a friend with a machine - this is your best option if this is something you don't anticipate doing more than 3-5 times/year.