SignTorch would be the best one to answer, but this is the way I would do it. Plug a USB memory stick into your laptop. Download the files you want onto it. Then take them to your CNC computer (since most CNC computers aren't connected to the internet). Then you should be able to load the DXF files into your SheetCam or equivalent program to create your .tap file. Some you may need to resize for your use so always look at the files before cutting.
If I'm wrong on any of this, SignTorch should be along to correct me.