Hello!
Have you successfully connected to the PC prior?
Usually with LG you have an option after you pull down the notification shade. It should provide additional USB options to change how the phone performs when plugged in. I will say the biggest time saver is just trying a different USB cable. Usually this will actually fix the issue. If you have another micro USB cable lying around i'd try it first. Secondly, look at file explorer on your PC and see if the LG device is showing up at all. If neither of those options work, there is a LG driver for PC, but let's see if these other options fix it first!