Once you download your free STL or BMP file, you cannot simply double-click it. You must import it correctly to create a relief.
Several platforms host high-quality, free 3D models specifically for CNC routing and ArtCAM: DXF Downloads free artcam relief files
Learn how different bits (ball nose vs. V-bit) react to 3D depths without risking a complex design of your own. Once you download your free STL or BMP