Unplug and plug in router. Move close to the router (try this step first). Restart iPod. If all else fail try full erase. Update (01/13/2018): Is the iPod used? Or new? A used iPod might need the Wifi antenna replaced or it could’ve come disconnected. Most of those are little (coax) cables but they look different in a phone or ipod/iPad. I wouldn’t suggest doing this yourself because iPods are the hardest Apple device to get into unless you like soldering. Sorry for the late reply. I hole this helps if you’re still having the problem
You need a new front camera assembly. Sometimes when only one camera doesn’t work, it can cause the other one to show up black and disable flashlight. I have experienced this before. I believe the front camera or something in that cable shorted out. Prevent this by turning your phone off before screen repair. Sometimes they are too cheap or short out for no reason.