Sorry I can't help you but Keep trying different things and eventually you will get it!!There is always a learning curve when you get a new machine. I know mine does far more than I use so I try to learn just one thing at a time and sometimes it takes a couple of days. the best think it to just walk away for awhile. Meantime just have fun and enjoy your new machine.
I don't have this machine but looked it up and there is a you tube video showing the plugging in.
Have to loaded your software to your PC?
I'm sorry I can't help with your embroidery machine or pc problem. All I can do is lift you up and hope that things get better for you soon. Sometimes when things happen, it seems it is one after the other. Try to stay focused, time changes things. so maybe it won't be to long you will be through the worse. Like rescuer said, 'Hang in there' we are here for you!
I do not have a Janome, but make sure you have connected a usb cable from the Machine to the PC. The square end goes into the embroidery machine. The other to the PC.
If you have done this and still receive the error, perhaps someone with a machine like yours will be along to help.
Hang in there Brenda. We care about you!