Machine design files for milling (even 5-axis) are relatively simple to set up. The following is a suggested order for the required steps.
Unfortunately you must complete steps 1 to 5 before you can try to simulate even the most basic toolpath motion. If you have rotational axes, omit them at the beginning and use only 3-axis linear motion until you have confirmed that the tool, stock, and table are interacting the way you intend.