Unable to transfer files to usb

Hi have just bought the dual usb. All I want it for is to down load SVG cutting files to use on my electric cutting machine. The files are usually zipped. Using ES file explorer I am able to open them but I can’t work out how to put them onto the usb. I have spent 2days trying to work this out,  when I click move to dual drive I get a list of Android then Lost and Memory Zone.  What are they all about.  Is there a manual to read.  I’m using a Lenovo yoga tablet and motog4plus. No success on either. Any advice welcome. Pls don’t use jargon