Failure to connect may be due to wrong USB driver, wrong board selected (under tools), wrong port selected (under tools)
or maybe even a bad cable.
I will not suggest more than at for now as for me it all old hat and I'd likely skip a step critical to someone new at it also
unless you are using Mint Linux version of the IDE what you see might be different.
However if its new and does nothing are you sure power is getting to it?